Amazon offers Prime members the Accutire Digital Tire Pressure Gauge, model no. MS-4021B, for $8.87 with free shipping. (Non-Prime members can spend $35 or more to qualify for free shipping; otherwise it adds $6.51.) That's the lowest total price we could find by $3, although we saw a similar model for $2 less a month ago. It features an LCD pressure display and lithium battery.