pawnbrokers have terrible prices on scanners. In fact, most of the time used scanners are NOT a good deal. Unlike other types of radio equipment, there is no bennefit of going with an older unit. In scanners, generally newer is better.
right now
www.scannermaster.com has very good deals on GRE scanners.
The PSR-100 is only $80, down from it's normal $100. This is the scanner to buy if you do not need trunking. Trunking is important, but not exactly 100% needed depending on where you live. I live in central Connecticut, which is one of the densest regions in the USA. The listening radius that I have on my scanner is about 20 miles. Within this radius, only 5 or 6 cities are trunked. My local PD and PD to each adjacent city are not trunked. In fact, some towns around me are dumping their trunked systems and going back to conventional.
Now, say you do want the ability to hear trunked systems, you would step up to the PSR-300. Excellent scanner and the only thing you cannot hear are digital systems. The only digital systems around me are one town to the south, one on the edge of my hearing radius, and the state PD. I would love to be able to hear them, but a digital scanner costs far too much for me to spend on this hobby right now. The PSR-300 is on sale for $169, down from $199. I have had one a year and it has been a VERY good scanner. Holds many more frequencies and you can Alpha-tag them, which means that you will see a name you type on the screen when the scanner stops scanning. i.e. On the PSR-100 you would see 460.5500 and hear a police dept. On the PSR-300 you would see 460.5500 ENFIELD CT POLICE and hear the police dept.
http://www.scannermaster.com/GRE_Scanners_s/284.htm