I have 3 Serena shades coming in about a month, and need to run power to the windows for them (existing construction, not new). Does anyone have a recommendation for a less expensive version of the power supply? Paying $900 to power 3x 12 volt shades seems absurd. I’ve come across a few posts recommending a power supply from Monoprice.com, but the link is dead and I can’t find the product name. Thanks!