From our pins in the mod comments roughly 2 weeks (from the first time we've seen it, that is, so perhaps even longer). There is also another sale at 500$ on the previous suggestion which supports the data point here. With just one sale at 256 on mptf I would be fine excluding it and going conservative, but with a second data point there - especially seeing how it's now relatively close to the high end sale - I think a range is better here