You would waste a sheet of ACM (cut 2' off it long ways) and only charge $75?? The sheet itself costs almost that much. Why a site survey and all the dog and pony show crap. Make the thing, have your van stocked with stuff you need and just go do it, figure it out when you get there.
An honest answer to the OPs question. If it is wood siding like T111 use coated decking screws or pop it in with ring shank nails. Concrete or block, tapcons. Anything else, you will have to figure out on site. You don't need a professional installer, this is nonsense work and not something anyone should really have to ask how to do. I've seen how some of these "professionals" install crap and my kids could do a better job than some of them.
My cost is $75, my sell price is $125.00. That's a 40% margin. That leaves me 20% for overhead and 20% profit. Note: I outsource the printing and fabrication, and we pick up finished work once or twice a week.
A permit is rquired in my town. That would be the cost of the permit added to a $95.00 permit acquisition fee. The city engineer (and the building owner) will want to know how the sign is going to be attached, and will require specifications for the fasteners. I need to survey the site to figure out what I'll need and provide the permit information. Add the cost of the fasteners and the time to order them (I use McMaster-Carr to avoid wasting time going to the hardware store). Add in drive time and minimum 1 hour for the install.
Maybe you live somewhere where you can just sling signs up without a permit or engineering. The "dog and pony show", as you put it, is fundamental to installing signs properly, safely, and legally.