Best guess is a couple of hundred dollars. Solenoids run around $60-$80, (depending on which one, you need to remove the transmission oil pan and filter. The big cost is if the valve body has to come out to replace the solenoid, if so you would expect to have to pay for 2-2.5 hours of labor, then the cost of filter kit, solenoid and the fluid. It might be higher labor, due to this vehicle having the solenoid and valve body under the side cover. Good luck.