Radio Hack used to have the cheapest crap known to man. You might check with Electronics Supply.
I went and picked up some at Walmart last night. They are huge. I am using them for mock up. I ordered 3 different one's from electronics supply too though. They just take 2 fawking weeks to get here! The magnet on them is tiny in comparison though so it should be worth it. Thanks for the tip, helped a ton!