I agree with the earlier post that these are a fad. Once the nostalgia wears off, people will start dumping them for cheap. For $400, you can build a nice MAME PC and throw it in any old arcade cabinet. It makes for a great project and you can get exactly the setup and games you want with better performance. Just buy a license for Launchbox and *acquire* some ROMs from the internet and you're ready to go.
If the nostalgia ever wears off, then at least you have a PC.