It should be <5k to install. Of course depending how far you need to go for the gas run etc.. but it's only maybe 1-2 hours work for someone with the gas line,

It should be <5k to install. Of course depending how far you need to go for the gas run etc.. but it's only maybe 1-2 hours work for someone with the gas line, and 1-2 hours work for an electrician. Source: Have a whole house gas generator