Waterproof bag/housing for my Nikon D3100?

So I'm going to the beach and I really need to find something trustworthy and nice to make my Nikon D3100 waterproof and take nice semi-underwater pictures.

I saw a waterproof housing box thing on some website and it was like $2000.

I want something dependable yes, but not something more than my actual camera.

Please give me nice answers and not just throw links at me.

Dicapac makes waterproof bags that claim to be able to withstand several meters of water pressure.http://www.dicapac.com/new_eng/index.html but even those are not cheap. Amazon sells them, a dslr model is about $80