I'm
with Bludawg on this one. Same thought came to my mind........call a Tow Truck/Wrecker Service. Even their smaller 1 ton trucks have extendable booms. Wouldn't take much for it to back up to the wall off of Maple Dr. and hoist and drop it over the wall. Might tear of some of the landscaping, but if the landscaping is your/or your responsibility (easement), they would probably do it for a lot less.
OR, if you happen to find someone in the area getting an AC unit lifted, the operator might do a quick side job for some extra money. A buddy of mine works for a large AC company locally......he gets calls from smaller company AC guys all the time to lift units. He does it on his lunch hour and makes some quick side money all for himself. ($100 bucks a pop and gets 4-5 calls a week.) He shouldn't be doing it.........but, Oh Well. His choice ultimately. Same thing for tow truck operator. Could ask one in the area if he'd do it. At the very least, he could tell you if it would be possible using a tow truck.
Bob