Instead of using 3Dmark, why not install the games and decide if the performance is acceptable for you? If you're a serious gamer, then a desktop sounds like a more logical choice (more options, better performance, cheaper).
I personally wouldn't determine the worth of a laptop/desktop just by running 3Dmark. 3Dmark, or any other benchmark does not give me scores that I can use to tell me the performance I will get in a game. Yes, the bigger the score the better.
And if you think I don't game, I do. I built a desktop 2 years ago for my games. I never ran 3Dmark. Instead, I installed the games I wanted to play and went based off of ACTUAL performance.
The only time I would really rely on a benchmark is to help me compare performance between 2 computers. That's really the main objective of it. It really doesn't help you determine game performance.