Wood vs. Composite Decking Material

[Christopher Boggs]

I am in the middle of a rehab on a future rental property. The current decking was only 2x4's and was damaged by a leaking roof, so I have to replace the decking boards and railing. I can't decide whether to use composite or treated wood. I know composite has lower maintenance, but wood is cheaper. My buddy owns a lumber yard so he gave me some pretty good prices on some closeout Trex Origins Composite. Also both prices below include brackets, screws, etc.

Approximate Rent - $900
House has blue vinyl siding
Deck has a brand new roof over it
I just installed a new support beam, posts, and sistered the roofing joists

Treated Wood Decking and Railing - $640
Trex Origins (grey) Composite Decking and Railing - $1140

What do you guys think I should do?

Does anyone know how long the paint/stain would last on a wood deck that is covered?

This picture was taken before I finished installing the new beam, but here you go - http://imgur.com/WQa7H