Reddit mentions of Disposable Kodak Camera [Camera] 3Pack

When I read "cheap camera with a built-in lens", I immediately thought he was describing one of these: https://www.amazon.com/Disposable-Kodak-Camera-3Pack/dp/B000OFW65I

Having done clubs for cash, I can tell you the standard setup is dSLR with a big Speedlight. Speedlight alone is going to set you back more than your budget.

You might have luck with a few of these...
http://www.amazon.com/Disposable-Kodak-Camera-3Pack/dp/B000OFW65I/ref=sr_1_2?ie=UTF8&qid=1331019806&sr=8-2

Gear required for this shot can be found Here

In my experience the ASA 800 have worked slightly better so I try and use those.

As for the combo plastic mailer bags/film canisters/printable postage stamps I have tried a different approach. I have got a flat rate box pre-addressed and pre-paid to myself and duct tape this to the camera. I also duct-taped a permanent marker for people to write their e-mail on it. I think this way is easier since it is less stuff to do, less stuff to get separated, and less work for the end user. What do you think?

I might try and steal your idea about the pre-paid stamps with the irregular item because I don't plan on using a flat-rate this year. I think having the camera built into the box will be even better and less things to get separated. Any chance you live on the east coast (or not California) where I can build one and mail one a test dummy to see if the USPS will get it there?

Here's something in your price range. Unfortunately, even the cheapest of cheap DSLR's are $500-$600. You can look around for used ones though and probably get a pretty good deal.