I just got into caching a few weeks ago. I bought a Garmin GPS III off eBay. Love the unit, works great. I just got a newer GPS unit and have no need for two. The GPS III is for sale. Its probably about 10 years old in total, but is in great shape. Has a small scratch on the screen and some minor signs of use. For its age its in great shape.
https://buy.garmin.com/shop/shop.do?pID=72#gpsIII
I have the Unit, Car Power Cable, PDF Manual, USB to Serial cable.
The USB cable works great with EasyGPS for updating the unit with cache .loc files from the website. Took a few tries to get it all working right, so if you have any issues I can do my best to help.
I'm want to offer it to someone on here before I put it on eBay. So if your interested please let me know. I'm looking for about $75 for all of it. Flexible on price so please make an offer.
I can send some pictures if you are interested.
The thing goes through 4 AA batteries in about 8 hours of use. Less if you use the back light. Recommend rechargeable, but the car charger helps a lot.
Let me know
Happy Caching.