Two problems with that line of thinking:
A: Garry and Facepunch are completely loaded on cash, which means they do not need any additional cash to fund development. The money of people wanting to get into alpha would make no difference and only further overcrowd the game.
B: If Garry and the devs wanted more people playing, they wouldn't have closed down registration and (mostly) stopped giving out keys. There's enough people playing as is, many of which were not intended to join in the first place but got in thanks to reddit and other sites leaking the keys. When Garry, Pat and Helk want more players, you can be damned sure they'll tell everyone, but until then you just gotta wait, pal.
Sorry, but no amount of cash thrown at your monitor or begging over the internet for keys will get you in. You missed your chance that was on a seriously-short deadline, no big deal. Other things will come along my friend, so go find something else to do for now and occasionally check the news to see if more keys are released or the game goes open alpha/beta.
Seriously though, the game isn't that fun right now anyway, tons of glitches and hackers, just wait until Beta/Release.