I bought one of these things used on Ebay maybe 10 years ago for around $500.
http://www.dynafog.com/foggers/pje/t...azer/index.htm
I've got a pretty large area and use a permethrin insecticide in a diesel fuel carrier. Generates a pretty good fog. Do the lawn, bushes, poolhouse, and anywhere bugs like to be. Even stick the snoot in a gopher hole and fog under the pool deck. The insecticide concentrate was expensive too and cost somewhere around $300 then but was enough to make something like 90 gallons. The model I have is supposed to work with a water base too but I found the fog isn't nearly as 'foggy' as the diesel base. An exterminator friend uses a slightly bigger version to do the local fairgrounds in the Fall. http://www.dynafog.com/foggers/pje/g...agle/index.htm
The company has quite a variety of foggers.
Trick is to find one cheap. People that get them tend to hold onto them.
Al