Board Thread:General Discussion/@comment-1.36.218.18-20161024095924/@comment-4795804-20161117124706

If the systen hasn't been changed the price is counted from the towers' buy price in medium difficulty. So, neither the currect difficulty counts nor the sell value modifiers count.

All five tower categories (bombs, glue, ice, tornadoes and other towers) increase the plasma attack, so you should sacrifice at least $30000 from each of the 5 categories for the full effect of the main plasma attack.