Wow...$90 would be a steal. I spent several weeks looking and only found one for $100, but they were too far. Ended up with a 1/10 JBJ Arctica titanium for $250. Works great though and beats the heck out of running the AC low all day while at work.
a couple of $10 clip on fans blowing across the surface will do the same thing, keep my house at 79-80 and my 125 has 500 watt of MH 4 inches from the water and fans on a temp controller keeps it at 77.5-78.5