Buying unowned items. Possible?

FireBirdy - Dreamweaver

Is it possible to add an item to the buying side of the consignment shop if I don't have a sample item in my inventory?

EG: I used the last of my green berries but want more, no-one else is selling and the auction has none.

I'm hoping there's a little known trick to get a full list of common items to choose from without having to run out and harvest one first. I did a search and all I found were guides on setting a shop up.

XFIienx - Heavens Tear

U need the item, srry