What to do about so-called  "Charity Shows".

That's another branch of probably the same subject!   This is just one example, I'm sure there are many that can add their experiences.  Remember an example is just that - an example!

When I am asked to do a charity show, if it is a charity that I  am really willing to do the show for, I work out a deal with  them.  They pay me my regular full pay for the gig (this way I am not doing  the gig for free), and then I later write them a check for the agreed upon  amount as a charitable contribution for the event.  Usually it is the exact  same amount, but not always.  For example, if my regular fee is $500 and  they want me to do a charity gig for a reduced amount of $100 for example, then  I have them write me the full check for $500 and I write them a check for $400  as charitable contribution. 
 
The good thing about this is that they realize the value of the show they are getting, and they also get used to actually writing a check and paying this amount.  Then they appreciate my show even more (not just a "free"  act), and they appreciate my check with my charitable contribution to them  that much more as well.  When other charities or other events ask what I  charge, I can honestly tell them the full amount that I got paid.  And  I can write off the charitable contributions on my taxes.