...but it's only good to 100 feet. Some of the wrecks we were diving in Kingston were a bit beyond that, and I decided that a camera good for 165 feet would be better. Also, the camera I got has a rubberized case, which will stand the punishment of my dive bag a little better, I think.
This is a first camera for me as well, but I wanted something just a bit stronger and heavier than what I suspect the eBay camera is....
Just my opinion, but it isn't all that smart to go as 'cheap as possible' on some things. Shoes comes to mind, as does anything with a lens in it, like cameras and binoculars, especially if you want to use them under the water.
Good luck with your purchase...