Craig's List is certainly not for the weak of heart. Every purchase is an adventure- it may work, it may not, and there are no returns or exchanges.
Most sellers are honest enough to list condition issues- but don't assume perfection. Ask them to be specific about damage, and then do your research. If you find an incredible chair with a broken leg, are you capable of patching it up yourself?
Be a savvy buyer and inspect your item inside and out before you hand over your fist of bills. A hasty decision can lead to a lot of frustration... or a broken waste of money in your basement.
Early on in my CL career I spotted a pair of enormous ceramic lamps and fell in love. I bought them without even plugging them in. At a mere $5 each, I'm sure I would have purchased them in any condition- but I certainly wasn't prepared for what I found beneath their gorgeous exterior. When the bulbs wouldn't light up, I dismantled them and discovered that the 50-year-old wiring had melted, rusted, burned and disintegrated. They needed to be completely rewired. No big deal for a standard table lamp... but did I mention that these are about 3 feet tall and use two bulbs each?
My local lamp repair shop gave me a discouraging news- their conservative quote was $90 each. OUCH.
My second idea gave me better results. I put up a post on Craig's List describing the work that needed to be done with a photo of the lamps. I received dozens of offers- all between $40 and $90 total. I highly recommend going this route if you lack the time, skills, or tools necessary for a particular task. This is a tough time for electricians, carpenters, painters, etc, and many are looking for additional income. Do yourself a favor by finally getting the job done- and help out a member of your community as well.
In my case, I realized that I needed to uh... shed a little more light on the problem. I did some research. Lamp circuitry is not a complicated puzzle, but while most lamps have 2 wires, mine have 3. Adam and I drew out several diagrams until we arrived at our solution (and he assured me that a little trial and error probably wouldn't hurt me too bad).
I purchased all the lamp parts I needed for about $25 at Home Depot and set to work. It took about an hour and a little cursing to get the three wires to their correct destinations, but at long last, the MOMENT OF TRUTH. I held the fire extinguisher at ready as Adam plugged it in, and...

it worked!
The moral of the story? If you really love it, put in the effort to make it work. And if you find out it's a Hollywood Regency Era Chinoiserie Lamp worth a couple hundred? Well, that's just the cherry on top, right?