I have basically zero problems with Early Access as long as it is clearly labeled that way. I also don't mind them charging full price, or really, any price they want. If someone wants to pay full price or even extra to get an early look at the game, why not?
I play way to many games to actually participate in early access anymore. I actually did buy Minecraft in Alpha though. I wouldn't want to go back on that decision since watching that game develop and turn in to an insane world-wide experience was great. However, I sometimes wish I could forget everything I knew about it and start from the beginning so that I could experience the current version of the game "fresh". So, now I prefer waiting until the product is close to finished.
Even that plan is a bit difficult though. I'm super-interested in Prison Architect. It's been "Early Access" forever now and even goes on sale.
Anyway, it seems to help the developers (through funding) and it offers an interesting experience for those who want to take part in that. As long as it is not deceptive, no problem.