I've done SEVERAL home cleanouts. My trailer I use for these is 6'X10' with 2' rails.
The most I've ever paid (pay by weight) at the dump was a hair over $26 (for one load). Most I've ever paid (dump fees) is +/- $70 for one home (3 loads).
Now....you gotta figure your hourly rate + fuel + Any special tools needed.
I figure out how long I think it's going to take me (hours) and figure $100/hr.. That includes EVERYTHING mentioned above. It's worked for me.