Replacing Roof

I have an older mobile home that is leaking. I had tried to cool seal it but didn’t work. Now I’m trying to figure out the most cost effective way to completely re-do the roof. I can’t put a metal roof on top because of the weak structure of the home. The best solution I have found so far is to do a rubber roof at $2.70 / square foot. Are there any cheaper way to re-do the roof? Or does anyone know a contractor that will do a rubber roof for less than $2.70 / sqf in the Tampa area? Any input will be appreciated.