When I buy for example 1 bucket or 1 sign via /buy sign 1, /buy bucket 1 I'll get two Items. One can be used normaly and the other disappears on right-click. Don't have any idea why that happens...

I think I know why, though the only way I know of to fix it causes bought signs/buckets/etc to stack...
Or at least bought tools.

Should be fixed now, added a != 0 check so it won't give a stack of 0.