Bike shops are forbidden from adding engines, it voids any warranty.

The three frames I use are the Schwinn Jaguar at $135 plus tax (available at Target and WalMart), the Sun Retro 7 Cruiser, which is the one I use at $260-280 with the 12inch saddle, and the Sun Comfort Rover, which fully decked out with heavy spokes, slime tubes, tire liners, mirrocycle at around $350.

What I've heard, especially one customer in Vestavia who called all around, those two Suns are about $25-50 more in your neck of the woods.