Jumping with rental gear - $~60-100.
Jumping with your own gear (in this case, none) - $~20-30

Having a friend that you trust to catch you after jumping out of a plane naked - priceless.

As a sidenote, this is the place I dive at and have no idea what the prices would be elsewhere.

I also doubt any professionals would allow you to dive without a parachute, you'd probably need a friend that is a pilot.

I also got dive certification through military training, and have no idea how much it would cost/how long it would take to get certified as a civilian. I just threw out that comment because for me personally, I can go down there in full gear and skydive for next to nothing (because I've known the owners since high school).

I know I sure as hell wouldn't try anything like this, and I certainly wouldn't trust myself to accurately catch someone within 45 seconds.

I guess my idea of "cheap" makes a lot of assumptions, but by god it can be done!