Check out godaddy.com. They're having a sale on .info sites.

I'm not sure you can find an already registered domain for under $10, but try sedo.com or afternic.com.

Domainrightnow.com have .info names for $1.95 a year at the moment also and the recent drama with Mark Madsen and p2p.com looks like was sold through ebay.

If your plans involve selling on the domain name quite quickly and you are looking for very cheap domain names check the small print in the terms and conditions of the supplier you choose. Some resellers still charge for transfers.

godaddy and namecheap offer .com domains for under $10

Godaddy is okay, but I prefer Namecheap. Also, do not purchase hosting from the registrar you decide to use. It is best if you keep those two functions seperate in case there are issues down the road.