Scout out fb marketplace and craigslist for Steelcase chairs, as they’re pretty common in offices and last forever. You should be able to find some without too much trouble, being sold after an office is closing/moving buildings. I got a leap v2 for about $100, but $250 is more common. The things are built like tanks, and even if the seat is in rough condition, you can buy replacement foam/covers and very easily replace it on your own