Walmart offers the Pyle 2-Channel 300-watt Car Amplifier, model no. PLIPA2, for $18.89. Choose Site-to-Store pickup to dodge the $4.97 shipping fee. That's pennies below our mention from two weeks ago and $6 under the lowest total price we could find. It features a 3-way electronic crossover, iPod direct audio inputs, and adjustable gain control.