I’ve bought android tablets for about that price. I’m sure you could too - but don’t waste your time, they don’t have enough power to be useful for anything. There isn’t much difference between a picture frame and a tablet - both have a CPU, RAM, software, and a screen, it is probably cheaper to power android (and put picture frame software on it) than to write a new custom picture frame from scratch. Wifi and RAM is built in to several CPUs these days so probably isn’t even an extra cost. There is a small cost for a touch screen, but not much - might even be cheaper just because touch screens are more common and so you get volume reducing costs.