I paid 650 for powdercoating my approx 18' long 2 ton frame, as well as a bunch of other parts, all as seen here:
http://rides.webshots.com/photo/2858777480080251109QvHMaJI also paid 350 for sandblasting the same, probably could have found a better deal on that part..
Sandblasting is the same expense for either painting or powdercoating.
The part to consider is the cost of good primer, paint and labor as compared to the powdercoating cost. When I did my frame I decided powdercoating was cheaper, and a better final product, also easier for me to do/have done for me.
Grigg