The concept that informs this "Aryan pricing" ideology the book seller orients himself on is based on the antisemitic stereotype of 'unfair pricing done by Jews', then (and now, don't search the net for the word) called: "Judenpreise" (hereafter JP).
The context for the precise quote that informed this question seems to be an American citizen, not a German, as detailed in Mark Johnson's answer. As this American in the memory of the reporter seems to base his reasons on NS ideology, it is still interesting to see whether or how Nazis followed this principle in reality, and if they made this into actual law.
Interestingly, these JP were variously perceived as too low, undercutting competition and enforcing a lower quality standard across the market, as well as too high, derived from monopolies or usury. These folk explanations were already described, analysed for example by Werner Sombart in his (1911): "Die Juden und das Wirtschaftsleben." (1911) Sombart later had allegedly ties to national-socialism and his personal views are difficult to ascertain regarding antisemitism as a whole. But in that book he nevertheless offers a much more differentiating view on the subject matter, that at the very least explains this race around pricing goods as a more 'natural' development within capitalism (than the true NS-conspiracy thinking).
It seems unlikely that this pricing regulation – and the consequential effective stifling of competition via prices – ever went into actual law during the third Reich. Checking changes to the German versions of laws pertaining to business practices does not reveal anything obviously relevant to this 'pricing things preferably (not) to .99 numbers'.
What Nazi legislators did do was enshrining into law the Rabattgesetz that was in effect from 1934 to 2001. It regulated discounts and allowances within a very tight frame – to ensure "more honest prices". This was officially 'directed against Jews', as they claimed at the time. This had no direct relation to consumer end prices in the sense of 'no mathematical effect towards or a away from .99'. It was said that if a sale was to be finalised significantly differing from the price advertised, this would be sign of dishonest starting price, and it effectively prohibited any form of haggling, systems of rebate and so on – it is said.
More on Rabattgesetz in Götz Aly: "Rasse und Klasse", chapter
"Handfeste Brauchbarkeit – Das Rabattgesetz oder die Freiheit des Feilschens", (p 61–64), Fischer: Frankfurt, 2003:
In all naivety, the twist pointed to the origin of the law, which at the time was explicitly directed against "haggling", the "alien merchant spirit of the liberalist system era" and the "Jewish grocer soul". Already on May 12, 1933 the law for the protection of the national retail trade had prevented the "evil of the encumbrance system", on November 25 of the same year followed the "RabG", the Reichs-Rabattgesetz. Both laws aimed at the "purification of competition" and the fight against "degeneracy", as the commentator and co-initiator of the law, Elmar Michel, wrote. His work appeared in 1934 and 1957: "Nothing needed to be changed in its main features," it says in the second edition. Why should it be? Michel was first a member of the government council in the Reich Ministry of Economics, then a ministerial director in the Federal Republic. No, he got excited in 1957, the RabG "contains no typical National Socialist thoughts". After all, the "fight against department stores was not limited to the NSDAP". Last but not least, Michel himself had already worked on the law in 1932.
So, while this does draw on antisemitism and was enacted under Nazi rule, it was devised before and in effect long after.
Nevertheless you can imagine that the most hardened antisemites in Germany were all ears to believe every crazy theory that somehow blamed 'the Jews' for something. Especially Julius Streicher seems to not have known any limits for absurdity in believing and promoting antisemitic accusations. His own newspaper is therefore an example to analyse. From a search through advertisements available on image sites from between 1933 and 1945 it seems very obvious that not all products were priced evenly. But as Streicher was one of the biggest haters, are ads in his paper conforming to this "Aryan pricing" theory?
"Der Stürmer" No 12, March 1938. Prices of the paper:
- 20Pf per weekly copy, 84 Pf per whole month, price per ad-unit: 75Pf (100 PF = 1.00 RM)
Ads giving prices in that paper:
- Watch: 15.00 RM
- Admission to dance with food and drink: 1.00 RM
- Garlic supplements: 1 month package: 1.00 RM, 14-week pack: 3.00 RM
- nice shoes: 7,50 RM
bound books for a monthly rate of 2.50 RM by
- Hitler: 7.20 RM
- Göring: 6.50 RM
- Goebbels: 4.50 RM
- Rosenberg: 1 copy: 6.00 RM, all 4 volumes: 24.20 RM
Fatherland bicycles: 28.00 RM, 32.00 RM, 55.00 RM, 66.00 RM
book "Pfaffenspiegel" ("often forbidden, always available"), different editions, 2.85 RM, 2.85 RM, illustrated 6.00 RM, all 3 for 11.70 RM, in 2.00 RM monthly rates
offerings from the Stukenbrok catalogue:
- bicycle lamp: 1.95 RM, dynamo: 3.00 RM, bike: 39,50 RM, sewing machine: 135,00 RM, typewriter: 109.50 RM, wrench 1.85 RM, expander: 4.25 RM, musical instrument: 7.90 RM, watch: 3.50 RM, camera: 17.75 RM, pistol 8.50 RM, rifle: 10.50 RM
weight reduction pills: 40 pieces per pack, 1.43 RM
- sport shoes: 10.90 RM
- quit smoking pills: 1,90 RM, 0,35 RM more if pay-by-mail
- different models of pistols: 3.60 RM, 2.90 RM, 1.60 RM
- anti-grey-hair potion "O-B-V": 1,85 RM
- different number of pieces of cutlery: 24 teil., 34.65 M, 26.20 M und 14.30 M (bis 72telllg u. mehr).
- hair improvement water for women: 1 bottle 1.50 RM, double-pack 2.50 RM
- men's suit: 28.00 RM
- razor-blade sharpener: 0.75 RM
- bikes from 29.00 RM – 32.00 RM
- long shelf-life sausages: 5.30 RM and 4.80 RM
- piece of furniture: 25.00 RM
- plum jam: 3.60 RM, 9.30 RM
- webbed wire fence: 4.90 RM
- roses: 10 pieces 3.00 RM, 1 piece 0.50 RM
- musical instruments: 27.25 RM, 8.75 RM, 4.25 RM, 4.40 RM, 5.65 RM, 21.75 RM, 53.00 RM, 130.00 RM, 96.00 RM, 67.50 RM
- bikes: 32.00 RM, 36.00 RM, 45.00 RM, 52.00 RM
- outdoor rubber clothes & shoes: 8.75 RM, 10.50 RM, 3.90 RM, 9.90 RM, 12.50 RM
- coffee grounds roasted: 6.20 RM
These prices do look somewhat simplified.
If you compare that to how the same paper complains explicitly about JP in "Der Stürmer", No 5, February 1932:
But that numbers ending in 9 weren't taboo should be quite clear:
This might still seem like a real effect to observe: "good national-socialists avoided prices ending in .x9"? Well, not really. On archive.org you have an easier time researching catalogues from the era, compared to image searching the net for contemporary ads giving prices. You will notice that the disdain for listings of prices ending in .x9 is very evident for all catalogues from 1933–1945. But the same effect is seen for pre-1933 listings, and also for listings after 1945. For larger sums, round numbers, .5 or .25 are represented more often than today. For smaller items with this effect seems unobservable
Psychological pricing towards the .x9 limit seems to just take its hold much later than in the US. But as this supposed effect isn't restricted to decimal places, but also applies to for example 990 RM compared to 1000 RM. Then we do not have to look much further than the Volkswagen, which was planned from the start to be sold at 990 RM.