Take a look at the NAD L54, or they have a couple similar models, but it's a AM/FM/CD receiver. It's rated at 40 watts but they are quality watts. Plus you already have the CD built in.

You might also look at Onkyo's 9555 or their stereo receiver 8555.

RECEIVER=tuner/preamp/power amp in one box. Usually cheapest option but lowest performance.
INTEGRATED AMP=preamp & power amp, no tuner
POWER AMP= just the power part that drives the speakers with no volume or other adjusts, such as the M501. If you plug your CD into that and push play your speakers would receive the full 150 watts with no way to turn them down. Unless as Feanor mentioned your CD player has a variable output.
PREAMP=the controlling unit and counter part to the POWER AMP. A preamp has the volume, input selector etc.

Don't buy just on a power rating. If keeping in a budget you might check around for a used receiver on your local craiglist or even thrift stores.

A bit over the budget but great bang for the buck, www.emotiva.com

www.spearitsound.com sometimes has good deals under their "demo & used" link. Not as low as buying from an individual but they back up what they sell.