Wow 50 BTC that's alot, i thought they might have reduced the amount of BTC paid to become VIP , especially now bitcoin price has increased to a nice rate . Base on most users comment I don't think changing of one name would be easy at all , but I guess the reason why is like that is for safety reasons.
It is indeed a lot especially to those who live in a third world countries because that amount of bitcoin in local currency would be a lot. So the best choice is to make is to make a request to theymos to change a username although as mentioned in other post that theymos rarely accepts these requests so it is still much better compared to donating 50 btc unless the required amount is changed or updated. I didn't notice anyone wanted to become a vip or to have a vip status and even requesting to change the required amount to become a vip.