My local animal control offers TNR for free but you can only drop the cat off on Mondays and Tuesdays and pick up the next day.
I'm certainly not going to hold a cat in a live trap for any number of days just so I can take it in on those two days.
I trap them on the morning of surgery. They get back to normal quickly after they are released.
My local humane society charges $65 per cat, but they don't hold those surgery days very often anymore so I use the local vet.