Hi all, every enchant in this game is limited via level (13-23-33-43) except insoles/riding chaps. Is this bug or?

Low level enchants are unsellables because everyone can buy higther one (with better bonus) at good price but not all chars are around range to get end-game craft materials.
I just wanna know if it is intended or just a miss..

Thanks for reply, sorry for my bad english