How much should I spend on a weight bench?

$70-$110 gets you a credible budget adjustable or flat bench that will satisfy most beginners. $200-$300 buys a noticeably more stable bench with a higher capacity, wider pad, and commercial-style frame. Above $400 you're paying for premium FID benches like Rep, Ironmaster, or REP Nighthawk class hardware, which the high-trust specialist publishers tend to favor for serious lifters.