I only have Oddworld Adventures 2. I haven't found OA1 yet.
I certainly don't think OA2 is worth $10... Get it free from...
http://www.games2play.net/download/index.html
You'll need an emulator. I suggest Visual Boy Advance from here:
http://gbx.consoleclassix.com/gba/gba_emu.htm
But you can't download a ROM unless you already own the game because that's
naughty! *wink*