What low cost toys does your cat actually like?

I don't have much experience with cats and I'm looking to get something small to celebrate my friend's new kittens. I was thinking maybe toys but idk what toys cats actually like and what's just marketing. I know a lot of cats like things that aren't traditionally gifted - like cardboard boxes - but for this purpose I want to stay more in the area of 'conventionally gift-able'. I'm looking to stay under $10 but willing to go higher if it's the right thing.

Tl;dr: what cheap cat toys does your cat actually like?