The thing about psychological pricing is it’s inelegant and unsophisticated.
If I say “Crab Cakes — 7”, and then I say “NEW! Crab Cakes ONLY $6.99!” you can picture which kind of restaurant you’re sitting in for each statement… and the latter is not the kind of place you’d take someone on a date.
I think it’s fairly telling that Epic doesn’t charge “$18.99/mo” for a UE4 subscription, but “$19”. Elegance counts for a lot.