Okay, now everything souns more clear to me. I will totally take a look at this quantities to choose more than one items on the market stand. And I'll do my best to impelment this in the next update, too. Thank you again for your exmplanation. I will also try to recreate the bug from the mine and "freeze", and fix that too.
Actually your axe can be upgraded, but it does makes it like "chop less times" to make the tree fall.