wetsuit in fresh water vs no wetsuit in salt water

I'm trying to decide which IM to try to get into/plan for next year, I'm leaning towards IMFL.  Around here all I have is fresh water and it's always wetsuit temperatures.  I know you're more buoyant in salt water compared to fresh water.  I figure you're less buoyant in salt water without a wet suit than you are in fresh water with one.  But how big of a difference is there?   figure it'll be hard to explain the difference, so perhaps people can try to give values to the buoyancy they feel....   maybe on a 0-100 scale.  0 = no wetsuit in fresh water, 100 = wetsuit in salt water.

what would fresh water with a wet suit be.... 70?
Salt water without a wet suit... 40?