Those really aren't lenses. They are cheap screw-in attachments that mimic a wide-angle lens. If you use them, don't expect great picture quality. They might be fun to play around with though.

You can buy a Sigma 20mm wide-angle in your camera's mount for around $400.00 or a Vivitar 19-35mm for around $150.00. Just do an eBay search for Minolta Maxxum 20mm lens (or just Minolta Maxxum lenses) and see what you can find.

If you ever decide to switch to a DSLR, your Maxxum lenses will work on any of the Sony DSLR cameras, from the A200 to the A900.