I put $40.00 total into Tribes Ascend, but enjoyed as much as any other game I spent that much money on.
It sounds like they're not going to sell certs. That being the case, the only thing you can buy that helps you win is the points booster and that so far is capped at 10%.
The P2 Beta seems a bit bland so far- I need to figure out how to use the VOIP comms better and the game certainly needs a lot of work.
The map design is masterful though- at least on the ground. The air game has a very low view distance and a very low altitude ceiling.
What P2 is going to need most are commanders- RTS style players directing the fighting. It sounds like they are moving in that direction but it's not real clear what the final solution is going to be right now.
3 months to go from now anyhow and I doubt the BETA is the sum total of development.