Several members have given you suggestions already. The local paper, craigslist, etc. Additionally, you can put them up for sale here in Private Sales. Too bad you don't have the Bridgestone Turanza EL400 or I'd take them off your hands immediately. I believe the OE Bridgestone Turanza EL400 is LRR unlike the off-the-rack counterpart.
Make up some flyers and post them up with a pic too. Most stores, laundry mats, sandwich shops etc offer a place. Ask friends and co-workers. As others mentioned....your local newspaper and craigslist. I am a little stumped at the question, but I think I answered in the way I understood it.
People who find they provide a low cost per mile? I think an obvious group would be low mileage drivers.
I live in so cal, and there is a large and thriving market for used tires, usually amongst poor mexicans. I actually bought used tires for my old car. When your car is worth <$1000, buying tires for 30 dollars each used is not unreasonable. So your answer to who buys used tires: poor people.
