This means that for foreign customers of yours, your product will have constantly fluctuating price. I personally don't find that desirable. Also, there is some considerations to be made for purchasing power especially for items like apps. $1 might be trivial in the US, but it may not be so in a third world country.

that's quite desireable, i mean it's what everything else in the world does.

No, not every good in the world is priced in US dollars and presented as a random number that changes every day

pretty much every good is sold on ebay

I never buy anything in dollars on eBay. Sterling, sometimes, but it’s euros 99% of the time.

Prices on eBay actually look like something a human would choose. On AliExpress on the other hand the prices are all over the place, with really odd numbers of cents, which I assume comes from automatic conversion from whatever currency they initially priced it in (not necessarily dollars at that point).

Not everything sold on ebay is priced in dollars either.

that was my point

They could offer stickiness settings, like only change the price once the FX rate has moved 10%.

Yes, they can have a set of rules to set the prices. But then it’s not that different from the current system, which really is not problematic in the first place. I know this is the place for pedantic nit picking, but the fact that prices have some granularity is very much a non-issue.

In any case, actually probably have such rules, just not public. I am sure they have sales people being paid full time to agonise over such issues.

Apple obviously uses some conversation rate internally when creating and updating these pre-defined tables. They could use those same numbers, with the same update frequency, with an arbitrary input price.

How much do you think about spending 5 dollars? How much do someone who earn 10 times less than you think about that exact 5 dollars? Price categories absolutely make sense.

The whole point is that it is not a multiplication with a conversion rate, it's a mapping that is not purely multiplicative, which has coefficients that in some regions may be significantly different than the exchange rate, that provides round numbers and stickiness to them, and avoids temporal fluctuations - prices in regional markets get adjusted when the ratio gets too far off, not with every change in excahnge rate, in order to reduce the frequency of price change.