I've seen 4-post lifts between $2-3k depending on where it was built.
My buddy has an American one ($3k) and a Chinese one ($2k). He said the big difference is the cheap one wiggles a little when you torque a bolt.
Both are safe and lock in.
I'll probably grab a cheap one for my new garage. I just need one for maintenance and keeping my underbody looking as good as it does now.