I would be willing to pay up to the retail if I really wanted it and if the bag is in mint condition. I would want everything that came with it, which includes the mirror, extra tassels, strap and dustbag. I would also love to receive the box but its not as important as the other items.
For an 05 olive First, which would have retailed for $995, I'd pay up to $1300 or $1400 if it was in great condition with tassels and mirror. If it was in perfect condition (absolutely no darkening of the handles), I might pay up to $1500.