I think you know what the sweet spot is for items on SF. A few of the more senior posters have said that price already.
Usually for used SC, (even if seeing as close to new) they range in the 15% range of retail. But there is also a range that they stay at that which probably would have brought yours closer to the $175 -$200 range. Which personally is what I would have paid for it.
Unless of course it was black without vents and included pants, then we are...