Usually when relying on such sales, you need to prove (beyond reasonable doubt) that the SCM sale listed is actually your sale. Typically this is only possible if there has only been one sale, unless the two sales are really far apart (e.g if youre pricing a nuts n bolts hat and you have sales ta 20$ and 300$, it's fairly safe to assume it's not the 300 one).

In some cases, SCM sales simply aren't usable because of that.

As an aside, sometimes SCM says "Sold 2" (or more) and then shows a value, in which case that value is the average value; in that case there's literally no way to tell unless you can confirm the sale.