Parks we stayed at have had them any where from $0.75 to $2.50 to wash, dryers are all over the place. I figure $3-$5/load and when I do have to use a laundromat (no FHU sites) it usually takes 3 loads to wash, 2 to dry, with shirts/lingere being hung up to dry. Which adds up pretty quickly. If you are paying electric, I calculated (at 12¢/KWH) it costs just over 25¢ per load in motorhome which would equal about 50¢ for regular sized loads. Short term payback for purchasing w/d.
Barb