Radiation Detectors?

I'm looking to buy a Geiger counter/radiation detector. My goal is to detect unhealthy levels in and around the house, mostly out of concern for the Fukushima or San Onofre contamination (I live in San Diego). I do not need high-end scientific gear, just reliable measurements of low levels to be sure we haven't picked up something that needs to be cleaned out. My ideal product would run on battery power or plugged in, so I could have it 'always on' (ie, set up and forget it), but take it with me or around the house occasionally.

Does anyone have any recommendations? I would like to keep the cost under 10 oz silver, if possible.