Needing a new preamp for my Axis Super Sport with MM90's and Piezo

Battery life is super short. I measured 17 miliamp current draw with battery installed and 5k resistance with battery removed and a cord inserted in the jack. This makes no sense according to ohms law. Also, a time or two experienced ferocious intermittent noise with the piezo. A quote from Ernie Ball is $205 for a new preamp that includes switches, pots, toggle, etc. all soldered in. I doubt if it’s available without the peripheral equipment. Ouch! This is an expensive guitar.