Spot,I must admit that I haven't read this entire thread so I am answering only your question.
First you are not a prostitute. You are a working musician who apparetly is good enough to be gigging four or five times amonth.
Are all the jobs perfect? No and they never will be either. But they atre jobs and each one has something that teaches and you benefit by beyond the money.
How many coffee house jobs befpre an attentive audience for low pay do you get? 1 in 5 maybe? Thats good ratio.
My band plays about 50 gigs a year. Some are low money and some are good money and a few are rediculous big money. And the best ones are the concert jobs that pay relatively low. Its the Wildrover/\Rambler Gambler songs played to drunks that allows us to do what amounts to pro bono work for others. And for me its worth taking every embarrassing penny they pay me so I can play on a stage in a restored opera house in Warren, Pa. every year or so.
Don