Man, I love reading this thread!
I guess I am a flipper by accident, probably like a few others. I just wanted a half-decent road bike, without spending too much. 5 years later, I think I am a legitimate flipper, but only because I can't resist a bargain, or a 'rescue-bike'. I have bought around 50 bikes in the past 4 years, sold half and still have about 25 in the garage. I have bought bikes with the express intention of reselling after a rebuild, and even with the one's that had hidden issues, I have managed to make a profit on.
My philosophy is not to sell something unsafe, or unfit. I prefer low to mid-range road bikes from the 80's and 90's (non-dept stores), with Shimano groupsets and Araya alloy rims, at a minimum. They restore beautifully; I'll strip, degrease and polish alloy parts (Mothers Mag), remove rust from every nut, chrome trim (forks/FR etc) using a wash, or aluminum foil/water and fully polish the frame. Bearings repacked or replaced, wheels trued (within acceptable tolerances!), cones adjusted and bearings checked. Cables replaced and housing, if needed. New bartape, if needed. Tires and tubes replaced, if needed.
Basically, once the bike is safe, it's all about the aesthetic; it has to look irresistible! I always photograph outdoors and with multiple close-ups, a good, honest description, and I am always responsive (within an hour or so) to inquiries. I usually use Kijiji to buy and sell on.
I still think it takes dedication to make any kind of a living at flipping, but as a way to finance a great hobby, it can't be beat! Here's a sample:
