i can care less if my customer buys their own generator or gets it thru me. I dont make squat on the unit. I only supply them as a courtesy. My money comes thru the installation parts and labor. When i give a bid the line items for generator are spelled out. But if the homeowner supplies the generator it HAS to be located on the gen pad and off the pallet and un-crated before i arrive. When i supply the generator i have a small charge for delivery to site, moving to install location, uncrating and setting unit. Those units weigh about 500 pounds.
I have a special delivery cart that cost me about $1,000. it allows 1 man to move and set generator. I don't bring that to a job unless i supply generator.
Generac DOES NOT require a GENERAC dealer to do service in order to protect warranty. Even a homeowner can do their own work with proper record keeping to prove work. HOWEVER it DOES require only a GENERAC TRAINED service tech to do any repairs that require generac to supply parts and labor. This is the same as most companies paying a dealer to repair their units.
Theres more parts than you think that go into a generator installation. I cant tell you how many times ive had customers tell me that they cant believe how much work and parts it took to complete the job. "No wonder it was so expensive".
In my own case, i've been told by several potential customers that my install price is too high. and to those i politely tell them good day. I never do check back to see how the job went. But i did get called back to 1 job that i had bid years earlier for a service call on a non working generator. The install was so poorly done, i refused to do the repair. The wires feeding house were too small, the gas piping to unit was WAY to small and they never increased the size of the gas meter to accommodate the generator,.I told them to call back the original installer to fix it. I can tell by the sour look that he probably did the job himself.