If it's a "buy it now" and I really want it, I buy it but don't pay until the seller has answered all my questions and sent through a detailed set of high res photographs, which I take my time going over. I only pay when I'm satisfied that I'm getting what I think I'm getting.
"Buy it now" means exactly that. If you want to satisfy yourself that something is as described, do that first. If someone did a "buy it now" and then started asking questions and requesting more photos, I'd tell 'em to stick it. Especially if they "took their time". That's time during which someone else could have bought it without dicking about.
Answering questions and supplying more photos and information is of course absolutely fine. But as a prelude to bidding/buying, not afterwards.
_________________Behind Bars: Collected Mountain Bike Articles ebook
- contains significant retro content