Forgive me, but I think I can read English quite well. There is a period after the $50. So if I cut up the lines the way he wrote them, it says:

the 4-piece band that cancelled was booked for $50.
less than I charge, so I played for their price.

So if he meant something else, he should have written it like this:
" the 4-piece band that cancelled was booked for $50 less than I charge, so I played for their price."

So who needs to learn how to read and write here? :-)

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Roland EXR-5 user - http://www.exr5.tk