You hear entertainers all the time saying 'If I couldn't get paid for this I'd do it for free.' When's the last time you ever heard a business person say 'If I couldn't get paid for being chairman of British Petroleum I'd do it for free'?
There's obviously nothing wrong with selling your art - only an idiot with a trust fund would tell you otherwise. But it's confusing to know how far you should take it.
