Anybody who is intelligent enough to set up a wallet and actually buy bitcoins are probably well off financially and don't have to sell bitcoins.
This is the reason why the price just keeps going up and doesn't fall. Bitcoins are like a rare collectors item and the more people who get involved the rarer they become.
When I first bought Bitcoin in April (yeah, timed it didn't I) my total net worth was around $2000. I put in about $1500 then, and gradually bought more during the summer/early fall with money I earned working. I lived like a Spartan and managed to save $150 per week to invest.
I have a diagnosis which makes me able to work only part-time. I've always been poor. Bitcoin changed that.. what I may have been able to acquire living frugally for 4 years eating only noodles, I now achieved in this one rally.
I've sold half of that, keeping the rest long term. Bitcoin has changed my life.. a lot. I can now for the first time afford to get my drivers license.