We currently have 2 power supplies on the way from 2 different Ebay vendors in China. One is a 36V 3 amp and one is 36V 4 amp.
These are so inexepensive, even including their shipping charges, that we would not be able to supply them and ship any cheaper. I believe that certain technology products get subsidized shipping via China Post.
We will be comparing each one and make a recommendation on the best one and the seller will then relist them.
36 Volts is fine with these solenoids as they only fire for 40 milliseconds each time.