What's the cheapest all-in-one printer that actually works well?

The Canon PIXMA TR4720 or similar models in that range usually hit the sweet spot - they're around $100-150 and handle printing, scanning, and copying without falling apart after a few months. HP's got some decent budget options too, but honestly you're gonna spend a bit more for reliability. Stay away from the absolute bottom-barrel stuff under $80 because the ink costs and print quality will drive you nuts. If you can stretch to $200-ish, Brother and Canon multifunction lasers are tanks and way cheaper to run long-term.