Guess it depends on a lot of things!
Some do it because they need the cash but that in its self can be a minefield! When does it become "enough" money? Would you do a gig for less than £150 a skull?
Some do it for the love where cash is not even in the equation, just a bonus!
Venue choice/asperations too is a big factor. Are you happy too do wee pub gigs or big venues and festivals, cash varies here from covering your costs too getting excess of £400 per gig!
I believe to get to a really high standard you need to rehearse at least once a week and gig at least once a month! All these things cost so I think you need to factor in what exactly you want from it!
Do you ever really make money if your reinvesting in your gear, petrol etc etc