If you're only camping in moderate climates where the temperature inside the RV is close to the outdoor ambient temperature, the double pane windows will have minimal value. On the other hand, if you're camping in extreme temperatures (cold OR hot) like we do here in Texas in the summers, then the double pane windows are WELL worth the money. In 100 degF temperatures, we need all the insulation we can get to cool the 5th wheel, and the double pane insulated windows in our current 5th wheel make a LOT of difference compared to the previous one that didn't have them.
Rusty