The way I see it, every vote is a point. I'm not sure if some votes give out more points than others. Say it take 100 points to get from level 49 to 50. Level 50 to 51 would require more points, lets say 130. Moving from level 69 to 70 might require 2000 points. That's my messed up understanding.

If someone buys in, they didn't earn their stake through rewards. This means they did not receive votes and can't level up until they contribute.

I could be wrong, but I don't think I am.