Many of us have asked the same question: why have nearly all of the donors and VIP donors who gave 10 BTC and 50 BTC respectively.
Because when they did, they were easy values to give.
It was people who were able to mine around 50BTC per day or per week. So offering 50BTC didn't seem like a very high value.
Honestly, these values between 2010-2012 don't shock me. If I had gotten into Bitcoin early on, I probably would have donated a similar amount.