Alpha and Beta testing are SUPPOSED to be about finding faults and bugs in the code, not about first look and feedback.
The fact that Frontier has conditioned the community to expect this just shows that greed, on both sides, is still one of the Seven Sins.
The idea that I need to pay extra to be heard is heinous.
I think it might have started with that intention before the game launched, and maybe there will be some good feedback that will come out of it but I think most people will probably treat the 'alpha' as early access & most of the game design & balancing is probably best left to professional game designers.
The stage you have in mind is presumably what David Braben & the community team have been playing around with