Looks like an aluminum tank. For $10, that's really good provided it has a good hydro stamp on it (under 5 years old). Otherwise, figure another $20-$30 to get it recertified so you can get it filled. Still less than you usually find good used ones for, or new ones.
Check with the better vendors, as well as your local HBS, for good rates on a new/replacement regulator. As I mentioned, if you can get the remains out, it could be worth it to rebuild it. If you don't have the tools to tackle that, then probably better off selling it to someone that can and get a [tested] good one.