I have been very pleased with the magellan units. I personally have the Magellan Meridian (the very basic version). I has the SPC capability, many different preprogrammed datums, and the ability to enter user defined datums.
It has served me well for about 8 years or so. I know there newer, fancier units out there, but I don't need anything more than what this unit does. I think I paid around $100 for it. I did pick up the cables to connect it to the pc, and the dashmount cradle and external power cable.
I have a few GPS points in the yard, and it can navigate me to them within 6 feet easy.
Hope this helps.
Edit: I just did a quick search for the Magellan handhelds on ebay, and there are many, many listed, some color display units for under $100. Mine is the monochrome unit.