Design firms frequently upgrade their hardware. So you can frequently find great hardware at very low prices. Also snagged a fully loaded Mac Pro trashcan for $1200 back in 2017 when they all went for the iMac Pros.

I spent $50 for each monitor and additional $50 for 2 x Chromecasts.

Net out, 2 x 24” auto-updating photo frames for <$200.