Depending on what model you're talking about, $150.00 is a absolute steal for Tunze powerheads w/ wavemaker.
There's not too many dealers selling Tunze electronic products in the US. Import tariffs, freight, hassle, etc. all add up to the phrase "Not worth the trouble." Too bad, 'cause Tunze makes great products. I can't quite figure out why no American manufacturer (other then Aquarium System's [out of production??] Gemini) make air-cooled powerheads.
You may want to contact Tunze (www.tunze.com) to inquire. I'm sure others on this board know of "affordable" sources for Tunze.