Amazon offers its Prime members the Motorola Vehicle Power Adapter MicroUSB Rapid Rate Charger
, model no. SPN5400A, for $4.10
with free shipping
. (Non-members can spend over $25 to qualify for free shipping; otherwise, shipping adds $5.74.) That's a buck under our December mention and the lowest total price we could find now by $2. This adapter is compatible with most devices with a MicroUSB connector.
Amazon Prime membership is $79 per year; however, Prime is free for college students for six months, and free for parents and caregivers for three months.