what is the going rate for a full floating dana 80(don't know if they are all full floating or not)

 

It really depends on the demand in your area. From your other thread, most yards near me have axles priced comparatively with what you have been quoted.

 

why are they dirt cheap for being such work horses?

 

Who knows. They are not typically used in the offroad world. No demand == low cost. They may rise in demand as other more sought axles get more expensive.

 

from my googling....HD dodge rams come stock with Dana 80 rear ends?

The problem with the Dana 44 is that its usually not of the HP variety. Whatcha putting these under?

 

87 K5 but after some research the gears are half the cost on a 12 or 14 bolt than a 80 and the fact that they almost bolt right on is awesome, but i might get the 80 just to hang on to b/c it is such a freaking beast

 

Like I said, you have to look at the total costs involved in all of your options. Doing any less will likely waste your money once your hip deep into things and realize what you could have done.