Buyer is currently super young

The item is rare, so small proof is considered enough since it's equivalent to the amount available in the market.

However, the only problem here is that the suggester is raising the price with that seller. Sellers can't raise prices, only sales and buyers can. He has a buyer which is the only good proof but what ツ JoXu ツ said, the buyer hasn't bumped the trade since he created it; making it look like the buyer is no longer keeping track/completely inactive of the trade. (therefore making that proof invalid).