You can't sell L4D on PC anyways, it is a one time activation only thing.
:neutral::neutral::neutral:what's the point of buying the game, turning around and selling it a few weeks later?
L4D/L4D2 do not support DX8 at all. You're still running in DX9. x3 said this in post 10.Ok, Grey.
On another note:
I put arguments at "-dxlevel 80" and "-dxlevel 81". I also used "cl_showfps 1" and I'm getting AT MOST 20-25fps. But, it's still playable if there aren't a lot of infected in the area.