Why is there a suggestion bringing it down? First of all, this suggestion isn't itself changing the value of the hat, it's reflecting a minor change in the value of that hat that has occurred since the hat was previously priced. It's going below the previous price because there's a sale there, which forms part of a group of sales that form a clear range. The fact that your sale happened 1 day ago does not change the fact that it's statistically an outlier. 1 month ago is not old in unusual terms, and using a 1 month old sale isn't idiotic ;)

imagine there was no previous suggestion and no arrow pointing up or down, if that helps. With 5 sales recently between 1.9 and 2.4, including 2.8 purely on the grounds that it happened most recently would be illogical. If another sells for above my range, you might then have a "more reasonable" case to base a new suggestion on.

EDIT: I notice you're sounding like I could have made this suggestion with just that 1.9 sale and dropped the price; that's not how it works. Forget the old range, all of my proof is active in supporting and creating the new price. It's a coincidence that the high end remains the same.