But despite many seasons(well over a decade) of 3 and 4 exchanges/ season, it was never enough of a priority to convert to propane.

In those years, we'd go through a tank a week while sailing.

Now the kids are off in school, we're using less these days. 2, 3 tanks at the most, which runs 150 to 200 for the season, or so, depending on where you get them.

We could never live aboard with CNG, that's for sure, but it's not likely I'll change it now.

Low $ side is 50 a tank, highest has run about 80. For 20 hours on a 4000btu burner, it's expensive up here.