Sorry you can't do this job unless you basically fully sub out the work. As far as charging $75 per yard of mulch including clean up, that LCO either mis-typed or it is not good advice. Depending on your area of the country, which you stated was an upper class neighborhood you should be able to get $60 a yard for mulch including laying it down. Plus your hours worked on clean-up, plus de-thatching areas of the yard, plus edging a few beds he wanted edged. You can $90+ a yard in upper class neighborhoods per yard of mulch.
But unless you want to try and sub it out to a big company and make a couple bucks being the guy in charge then you need to let him know that it's TOO MUCH work for you to do. That's a lot of work for a full-time 2-3 man crew. Personally with my dump trailer I can do 2-3 yards of mulch per hour by myself, anyone working for you is going to work two-thirds your pace.
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