Hrm, only post by this user, I'm thinking one of two possibilities:
2. Someone who knows *NOTHING* about Macs, honestly coming here to find out what is going on.
Assuming #2, then by the description, it is almost certainly a modern hack/mod. That makes it worth nothing as an Apple collectible, and its value is solely in whatever useful function it performs now plus possible "art project" value that is completely in the eye of the beholder.
If it is a "modern PC in an Mac SE shell", then it's worth whatever the PC components are worth. Probably somewhere between $20 and $100, depending on how old the "modern" PC is.