The one pictured is a natural gas driven 22kw with 200 amp smart transfer switch. Capable of starting a 5 ton AC unit and 95 amps of available power. About $5300. Add electrician and plumber to install gas line. Pricing to install depends on location of electrical and gas services.
Generally, my company does not do residential installs. We are primarily a commercial and industrial contractor. I could hook you up with my residential contractor for pricing. What size unit are you thinking?