so the entire site is above ground stones? Or are the newer sections monument styles? What is the frequency of trimming? Weekly, biweekly, what? With that spacing and that acreage, you will need probably 6 people working nonstop each week to complete the weekly services. Toss in flower and gift removal/work arounds and memorial and labor day, you better have a very substantial crew of help that is flexible enough to assist in those periods where the labor load is going to be extremely high. Edging is only pertinent to monument markers and drives, but without being on the site and knowing the full scope of responsibilities you will have, I doubt anyone here could even give you a ballpark figure to go from and have it be even remotely realistic. I will say that a site that large is not for a 3 or 4 crew company that already has a 75% or above filled schedule. Although the dollar signs may be flashing in your eyes, recognize the perils jobs of that scope can have for companies not big enough or ready to handle them. I've seen more than one company die trying to eat the elephant in one bite.