When I worked at an Ace Hardware, 2005-2011, I mixed a lot of Benjamin Moore house paint (acrylic latex) for a couple of Giant Scale RC guys here in Tucson. One was gas-powered; the other was Electric. They thinned it (water), sprayed it...said it covered very well and added little weight.
At something like $35-a-gallon it was certainly less expensive than dope, and was available in any color or hue desired. It could also be mixed in Gloss, Semi-Gloss or Matte.