A little north of your limit on price, but the
Denon DL-301MK2 is a bargain at $400. I bought my last one for a lot less when Comet Supply was still selling them.
What's your go-to cheapie cartridge?
Let's say $300 or less. This would be your "y'know, this thing is pretty darn musical even though I've got higher end carts" cartridge. In my case I'd have to say it's my 103R. Not as transparent or fast as a lot of my better carts, but it sails smoothly through the grooves and just sounds good.