I use only AFC solenoids. I much prefer to see them on the high pressure side of the regulator as I have come across two corroded out regulators in the last ten years. One is too many..

22.00 - 24.00 is about what I pay for the AFC #151. Xintex and others use this same solenoid and sell it for big money.... Xintex calls it the SV-1 and it sells for about 3X what I pay for the same product with a different sticker. I have never had an AFC solenoid fail me, not to say they can't or won't, but I have had plenty of failures of the low pressure style sold by Trident etc......