Some rares are more 'to keep' than 'to sell'. I would say this potato fits into the 'to keep' category.
Super Rare Potatoes--the last time I checked--were going for quite a lot. However, this was do to it being relatively new to the economy and whatnot. As it is presently, super rare potatoes (which are potatoes that have colored names and lores like heads do) aren't worth a lot because of their incredibly small market.
So: I've been a bit inactive for the last month or two. Are there any items on my initial prices list that are terribly off or wrong? Beacons aside, rares don't usually have huge fluctuations
Rip creeper heads. They're drastically decreasing. People would only buy them for 70-80 diamonds. You'd be very lucky if you'd sold one for more than 80 diamonds.