To be fair, if this is the only sale, I guess I would leave it unupdated, seeing the differences in the values on the sulph strontium (the sales there are pretty far apart). With none on the market atm and none having been on the market for a while, its hard to call it an outlier based on anything, though.

Also it seems like the sale was already outdated when you suggested ;p the sale is nearly 4 months old now