Once you sell an item you cannot get it back, young Wizard, but I'm sure you can find one you like in the Bazaar.
Just go to Olde Town and look to your right - there's a building with an awning sign that says 'Bazaar'.
Once inside talk to Elik, and he will show you all the items he has for sale. These are items that other players have sold him, so you'll see lots of things you can't use yet. If you want to only see items you can currently use, click the 'Usable' option at the bottom.
Then just browse the tabs at the top for all the different items you can buy that your Wizard can currently use.
You can also sell items to Elik, and he will give you a little more money for them than the regular shopkeepers of the Spiral.
