Would this motherboard be enough?
As a gamer and someone who doesn't know a lot about motherboards I can't see any real reason to get a $150 motherboard when a $60 one like this http://megacomputer.ca/index.php/main/Product/MBAS0224 has everything I need. Apart from only two memory slots and no crossfire would I have any problems using this for playing games like battlefield 3? Is there some type of increased speed expensive motherboards have that I'm not seeing?
There are many speed plusses to more expensive boards. But the board you list is not going to keep you from enjoying the latest games. The only drawback is the 95W limitation on the CPU. If your CPU is one in this list...
You will be able to use that board. If your CPU is of the 125W variety, you will want to look for a different board. Keep in mind, BF3 is a very CPU intensive game (from what I've read) So if your CPU is a fast quad core or better and you have a mid-range graphics card or better, you should be in fine shape. But keep in mind that the higher your monitor's resolution, the more powerful the garphics card will have to be. And the more powerful the card, the more work the CPU is required to do to keep up. If you are gaming at 1920x1080 (or higher) you will want a HD 6850/GTX 460 or better.