1. You can't use carrots and potatos in the shop. The shop will not recognize the item id's or names.
2. There is a typo in a message. I know you're german, but it's pretty useful to correct. So the typo is: You didn't have enough reSSource to buy this item! I could be incorrect, but I think ressource has to be resource!  I hope these chances will be made, and I will post other bugs or typos if I find them.

Not gonna lie, this is a very good plugin!