Once you join the Thieves Guild and you enter The Red Flagon - Cistern, there will be a guy named Cynric Endell shooting steel arrows at a dummy. You can take as many as you want as long as he's shooting. Not to mention all of the chests there you can take from.

You missed the oblivion forum...by 5 years.

Yup, that's correct. In fact, all NPCs have unlimited arrows.
Oblivion had the same system, and there was a guy training in the arena bloodworks, hence the previous comments.




Those were iron.
I know, the difference in damage and value is astonishing. :B

On a more serious note: not everyone playing Skyrim has played Oblivion before.