A quick search on EBay shows some results for $100. That’s also relying on the console to be in decent shape besides being heavily used, and you have to deal with getting a video adapter, which is like $20 for a cheap one or $100 for one with fancy features that makes it look nicer.

$250 for a brand new product supporting modern features like HDMI, USB, and Bluetooth sounds reasonable. It’s got a built-in video filter system like the fancier adapters, and if it’s anything like their previous products, ~~it will have support for mimicking other consoles of similar compute power (the original PlayStation 1 potentially?)~~ I checked and their website says it won’t support this feature. However, it does mention it has support for the Expansion Pack, which is another ~$70 although it’s only needed for a handful of games.

Their previous products have sold quite well, so there’s that.