[Kromm]

"Realism" is an ugly word in this genre, but: It's realistic for someone from away to turn a profit selling goods that are common at home but highly valued abroad for their ethnic cachet, as talked up in flowery terms by some merchant.

I wouldn't let it be automatic. The character would have to find the bow back in Elf-Land, front the purchase price, drag the thing to a non-elven town, and make all the usual rolls to sell it.

And I'd only let it work once per town, at least for that specific bow. The elf couldn't rebuy and resell indefinitely . . . the Merchants' Guild is famously canny, and more to the point, merchants who aren't elves won't be offering the racial discount, while those who are elves have the same discount on their racial template and will insist on claiming it.

If an enterprising elf with lots of capital wanted to buy two or 10 or 100 bows in Elf-Land and sell them in town for profit, that could work, too. There's a word for the risks attendant in carrying that much cash to Elf-Land, lugging all that valuable, heavy merchandise to town, and then dealing in arms in a town that has thieves (who will be after the cash) and King's Men (who will be very interested in both taxes and arms dealers). That word is "adventure." I don't see it as being any safer or less adventurous than killing things for the money; in fact, it sounds like a fun urban adventure.