What is proper behavior for late-game in Squadron TD? (especially in regards to selling towers)

Question

Generally speaking, a game doesn't give you options without valid scenarios in which to use those options. Specifically, there's probably a reason we're given the option to sell towers in Squadron TD, but I never sell them because I don't wish to waste what I've spent.

After wave 20, is, for instance, a Dark Mage worth keeping? Or is 50% of his paltry value worth putting towards yet more Lords of Death? Heck, I'm not even sure Dark Mages are worth building in the first place, considering how effective Fire Archers are.

The forums for Squadron TD are full of build orders and opinions, but low on detailed info, or advice for playing beyond wave 10.

Answer 1

I sell towers pretty frequently if I need just a little more to get me to the tower I need. I like the custom builder and use zerglings, so it's not a huge issue.

But usually I don't sell units because they're always good to take at least one hit from a wave before moving on to my better towers. It all depends on your build.

Also what if you miss click a tower? There's no other way to remove it (that's why it gives full cash back if you do it in the same round.) But yah, it's mainly used as an "oh shit" I need a lil more to get the tower I really need.