If you like ripping then maybe buy a variety of the cheapest packs you can find, ideally with 10 or more cards in each pack. You get a good quantity of cards, hopefully nab a few for your PC, and maybe even get a few particularly nice ones. I find the $10 for 3 cards packs to be such a downer, especially if one gets very little out of it (time spent ripping, cost per card, etc).
I also agree with Budler in that hopefully you don't feel compelled to spend all $300. If everything looks overpriced, look elsewhere.