there is an unlmited money glitch
if you sell monkey sub or Buccaneer you get more money back
200$ sub
50$ Buccaneer
this is a bug fixed in update 13.
also ice monkey. one more thing: if you upgrade any of those towers to tier 3, they sell for even more money
once again, every bug is patched in update 13. It’s going to be a massive update.
Update is out