Oxa via Amazon offers the DBPower DC Auto Premium Tire Inflator for $39.99. Coupon code "YJX3MVFN" cuts it to $19.99. With free shipping, that's around $22 under the price most third-party sellers are charging and $3 less than our mention from a month ago. It can inflate a standard mid-sized car tire from 0~35 PSI in 4.8 minutes, and features automatic shut-off and a backlit LCD.

Update: The price has dropped to $29.99 before coupon, $14.99 after.