One of the most difficult aspects of running a price guide is that some items simply have too few data points – and they’re spaced too far apart – to determine the most accurate market rate for the item. The more data points, the more accurate one is able to determine a more accurate assessment of value, or to predict future statistics. This isn’t a problem specific to PPG, nor to price guides in general, but one we definitely have to contend with. Our current valuations take into consideration 30, 60, and 90-day medians, and work out a calculation to come up with the Estimated Value. But what if there’s only one or two data points in the last 90 days? Or none? That’s where the change comes in.
Going forward, items with five or fewer sales over the past 90 days will be handled differently than others, and the calculation will be based on the previous five sales – whether they were all from 91-95 days ago, or go back a year or more. Because of this, you might see that some of the more rare items have seen a change (maybe drastic) in their Estimated Value. One entry that stood out for me is the Glow in the Dark Freddy Joker Pop. We only have three data points on this item – two in the $500 range, and another recent sale that went for $5000. Yes…that’s an extra zero. Based on our old way of doing things, this was sitting with a $5000 estimated value due to the $5000 sale being the only one in the past 90 days.
This brings up a point that we’ve expressed before, but I will say again. When it comes to the valuation of an item – particularly one with so few sale points – it’s always good to look beyond just the number in the Estimated Value. We show the sales history for a reason, so you can go back and look at past sales to see if there are anomalies, trends, or anything else that might sway your buying or selling prices. The GITD Joker is a fine example – one person paid $5000, two paid 1/10 as much, which tells us that the next sale(s) could be just about anywhere.
Update: We’ll be keeping an eye on anything with drastic changes to ensure we’re getting what we feel to be the correct formula. If you see any major, unexplained changes, just sit tight for the time being – we should have everything worked out over the next 24 hours or less.