John, the drain line on a frost free fridge will be located at the bottom of the evaporator pan. The evaporator pan is a pan which sits below the evaporator and collects all the melt water when the fridge defrosts itself. On some fridges it's fairly common to have that line clog up on you, on others, it almost never happens.
If yours is a top mounting freezer, just look in your freezer compartment for a removable panel. That panel will most often be on the back wall of the freezer compartment, but on GE 12 cubic foot fridges, the removable panel is actually the floor of the freezer compartment. Often the screws holding that panel on will be covered by pop-out buttons.
If it's a side by side with the fridge on one side and the freezer on the other, the evaporator coils will be in the mullion between the two sides, and there should be a cover that's removable from one side to service the fridge.
Once you have the panel off, you should see a fan with fan blades and an evaporator coil made of aluminum tubing. The evaporator pan will be under the evaporator with the coil tubing, and you should find a small (3/8 inch diameter or so) drain hole in the bottom of it.
Now, use a piece of stranded copper wire (with the insulation still on) to use as a snake to clear the crap out of that drain line.
Dried up food from the freezer compartment gets blown by the evaporator coil and by your shifting things around in the freezer and drops into the spaces where cold air gets into the freezer. When the fridge defrosts itself, melt water from the evaporator coil washes that food down into the evaporator drain, and causes the rubber drain line to get plugged.
My guess would be if you phoned around to 3 or 4 places, none of which could afford full page ads in the yellow pages, but only their name and phone number, they'd all charge considerably less than you were quoted to clean your evaporator drain line.