Interesting approach. Looks like both you and the seller were interested in creating a "win-win" with this transaction. Good for you!
A good idea when buying on line
A guy about 2.5 hours from me was selling Sonus Faber Concertos on Craigslist for $1000.00 including the stands, factory boxes and manual. I considered driving to him and even taking a receiver to test the speakers. Then I had an idea. I suggested he bring them to my house so I could listen to them on my system. If I wanted them I would give him $1200 ($200 more than he was asking). If I didn't want them, I'd give him $200 for making the trip. He agreed. They looked and sounded great and I bought them. I thought the extra $200 was well worth the guarantee of eliminating any problems and not being disappointed. Although, maybe I should have suggested $100!