Do you have more details on the Costco jack? If they have the AC Hydraulics jack I'd be very interested to know which model and price. Unfortunately no Costco where I live now, but I'd make a special trip next time I'm in Chicago.
I bought my jack at Sam's Club... it's a massive Michelin branded cheap Chinese import, $65 or something. I had to return the first one when it started auto-lowering now and then.
The new one seems better though at first it
wouldn't lower all the way without a load. Seems to have broken in now, hoping for the best. Get what ya pay for, I guess.