How much should I expect to spend on a decent dining chair set?

The picks here range from roughly $135 for a set of 2 to about $700 for a set of 4 with casters. Verified-purchase reviewers generally report solid value in the $250–$320 range for a set of 4, with diminishing returns above that unless you specifically want casters, swivel bases, or premium chenille upholstery.