There is a big expense in moving dirt. Digging dirt is cheap and easy, but moving it is where you eat up all your time and spend all your money. I personally bought a single axle F600 dump truck for $3,000 to move dirt. Depending on how far I'm moving the dirt, I can load it with my backhoe, get off the backhoe, get into the dump truck, drive it a thousand yards, dump it, drive back and get back on the backhoe in fifteen minutes. Four loads per hour, seven yards per load puts me over 200 yards in a busy day. With my Dad helping by driving the dump truck, we can do five loads in an hour.
I personally feel that this job will require a dump truck. I'm not a fan of dump trailers, but that would be better then nothing. You can sell it when you are done with it, but I've found that I use mine often enough that it's worth keeping around. Mine is a beater. It's not street legal and I'm always wrenching on it, but for the price, it's more then paid for itself.
My neighbor hires ten wheel dump trucks at $50 an hour to move dirt on his place. He moves a lot more dirt a lot faster then I can, but with two dump trucks moving ten yards per load, five loads per hour and renting an excavator at $100 to load them, he's paying $2 a yard to move dirt without doing any of it himself.