Richard Garriott and Alienware made a deal and right now you can buy and support the development of Shroud of the Avatar just for 20 bucks! They say that you will have to pay $25 but from what we can see in the account it is just $20. So who knows...
What you will get? Not only do you get full access to Alpha, Beta, and the final game, but you have full access to every monthly Pre-Alpha Release!
Just visit this Alienware page then login or register a new account throught their link and that's it. $20 are home and usable in your account.
Easy so what are you waiting for? It is only for a limited time. But don't expect full game. It is still pre-alpha!