cost of new rubber roof ??

I called for estimate over the phone couple years ago. I told them I didn't need a bid to the penny, just a good ball park number. Reason was I didn't want to bring RV to their shop until they had materials and ready to work on. I didn't want my RV sitting in their yard for who knows how long. Over the phone I was "ball park" quoted $100.00 a running foot, plus $50-100 for every opening. I was also advised that once the old roof comes off... if anything needs repaired/fixed (any bad wood) price went to their usual hourly labor rate plus materials. And don't forget you might need some new vent covers and other odd and ends. And was also given couple choices for thickness of rubber roof. Don't remember the mill thickness they talked about, but they were real close to a roofing place that has material for rubber roofs on buildings. On thicker rubber material the weight wasn't much of an issue, but price sure goes up quick.