How much should I figure in my budget for installation of a natural gas
generator? I'm looking at a 6-7 KW generator to handle refrigerator,
freezer, sump pump, gas furnace, computers, TV and some lights but not
Air Conditioning. It looks like I need an electrician for installing a
transfer box and outlet to the outside to connect to the generator and a
plumber to hook up a gas line. Generator would be about 20 feet from the
electric breaker box and the gas line.

There are a number of companies here (Central NJ) that will do the whole
job and wonder what a package price might be for everything that I
described above?

This may be a DIY for many people but DIY is not for me for this project.

I would do this in the Spring after all of the work on Sandy repair is done.