I guess you can't read. It clearly states at the bottom - "I'm all out of beta keys, sorry everyone." He's out of keys, which means that you cant get one, by paying or by getting one for free.
Oh, wow, you're sure friendly and helpful. Thanks, mister!
Do you even know how keys are made? He can make more and chooses either to not want more users in the beta, or doesn't want to bother with whatever he uses to create more keys. I guess being rude is just your natural reaction to everything?
I've given away more than 500 keys for the game already. I do actually need to charge money for it at some point, if I would like to be able to continue working on it.