I have several guinea pig cages for sale. They have been used, but still in good shape.
$20 each. I do have one that the plastic has been broke, it still works to hold pigs as I've never had an issue with it. I'd take $15 for it as I know these are $60+ brand new. These cages are big enough to house 2-3 pigs if you just want to have a couple pets or if you want to venture into breeding them.
picture is of a new one online. I'm more than willing to take pics if you desire... or just come get the ones you want. Different color of plastic bottoms. Same concept though.