While gMap is (and will be) completely free, there are already two places where you can buy premium content based on it.
Stronghold – premium template at Themeforest
Stronghold is a HTML5 template with very clean and modern design. It’s boosted with plenty of most popular jQuery plugins and I’m very happy that gMap was included.
DMXzone Google Maps
DMXzone Google Maps is a Dreamweaver extension for Google Maps. gMap is easy to use itself, but their solution has marker manager which I really like. It fixes one of common problems with gMap – 10 markers with address limit – by geocoding it and saving latitude/longitude to gMap configuration during setup. But I’m not sure if it’s worth 29 €