The generator itself runs about 3000 to 3500
An auto transfer switch can easily run another 800 or so.
mounting on a concrete pad running gas lines, new electric ties etc will vary by distance to you panel supply location etc...those big wires are expensive per foot...so there can be a lot of cost variation.
I have seen this "part" of the install run another 3000 or so.
with a propane generator using about 2 gal per hour at 75% load or so you are looking at an operational cost of $6 to $7 per hour just for the fuel...which would run about $150 a day.
Given the huge up front cost and the high operational cost, you would be far better off buying a LP fridge / freezer that could be fired up when needed. Lighting can be had with an oil lamp or two and heat with a wood stove (if this occurs) in winter. Every thing else is a luxury.
We have learned to adapt with our frequent outages and even developed our own celebration of it called "pioneer night".
14 KW runs around 4 grand. Install can range around four or five thousand. All depends upon fuel type, location of where the unit will be placed as compared to location of main panel, Type of connection, auto or manual. A 14 KW will run the entire house, unless your over 5,000 square feet. I would wait for a while Pat, There is a lot of price gouging going on and the numbers will begin to go down. All said and done with gas, electrical,, auto switch, pad, permits. Your in the 8 grand and up range.
In the past two weeks I have received 5 calls for generator installation. I am in the process of finalizing the numbers but I expect around $8000 is a good price give or take depending on fuel source location and type.
I would not recommend anything under 20kw for a whole house with a standard service, 10-14kw for essentials only. This would go higher if you have electric appliances. Running power is only one part of the equation. You must consider starting operations also. An AC unit will take 3 or more times the running current to get started. That's when the lights dim in your house. Anything with a motor will need extra reserve power to start up. If the generator can't handle it, it will shut down or burn out.
I am in NJ, so, if you send me an email with some contact information I can pass on an estimate to you. Numbers for my current bids will be finalized by the end of the week and I will have a good estimate for anything from 10kw up to 60kw.