Man, those pictures really show that bike was used a lot (some would say beat up--lots of deep scrapes)... and the tires look like all the middle tread was worn down...and the seat looks like it's possibly torn.
I hope it works out for you, but you have more guts than I do buying something, sight unseen, that shows obvious use and wear.
I have to ask the rest of you....do you take your bike in for adjustment every 3 months? I would have thought only people riding a lot would need that. I find an annual tune-up is more than sufficient for my "lightly used" bikes. Maybe many of you don't even pay for annual tune-ups?