The one I bought cost $500 and my signal worries are gone. Do a search on goggle for "cell phone signal booster". Only other option I think would be to look at another carrier.
they work i put one in i got it from www.smarthome.com you mount the main antenna on the roof of in the attics then the wire runs to the box which you try to position in the middle of your house and it has another antenna to pick up and re radiate the signal.