If you're gonna shell out 300, I'd get 3 or 4 packs of F1's rather than a bunch of nirvana F2's. Check out the prices with seedsdirect, heaven's stairway, and dr chronic. I know dr chronic and seedsdirect give freebies, and if you tell them you're gonna spend 300 bucks they might let you choose a few packs of nirvana freebies. The nirvana beans are 15 bucks per pack at SD.
I'm not a fan of DP, I think serious, and thseeds have better genetics. For interesting stuff you should check out reefermans seeds. He seems to be working will a wider diversity of stuff (asian strains, nepalese, burmese etc) than the dutch guys. He'll give you a lot of freebies too and you can buy single seeds of lots of strains if you want more choice.

peace