Also, 40k is an expensive hobby to get into if you want to play the tabletop game. It's much cheaper to read the books and play the various videogame adaptations.
To give an example: One Lord of Change is $150 on GW's online store, and still over $100 everywhere else I can see. That's one commander. Unpainted, unassembled. Now factor in all the other boxes you'll have to buy to make and paint an army...