That question is not easily answered.  A lot depends on terms, equipment, local demand/supply and level of service local dealer is giving.  And it also depends on how much the distributors are protecting their dealers.  I've seen it where the dealer was lucky to get $10 a ton for his equipment (plus freight) and I've seen cases where the dealers were making $40+ a ton.  Most I'd guess are making about 10 a ton (plus freight & shrinkage) if they are passing it thru their tanks, less if they are hauling straight from terminal to your place.

Now if you are going and getting a nurse trailer load at a time the margin will be higher.