Acer 1080p USB-C Portable Monitor | $130 | Amazon
If you need a second screen on the road, you don’t want to be lugging an entire monitor around, but when they’re portable like this 15" Acer, that’s a non-issue. Now $130 ($50 off), you’re getting a 1080p IPS display with a respectable 7ms response time. There’s just one catch: this one is USB-C only, so you’ll need a modern smartphone, laptop, or tablet that uses USB-C for video out, particularly one that supports DisplayPort Alt mode. Check your hardware to ensure it’ll work before ordering.