The card demands two cards to be sacrificed in order to summon, meaning the Alchemical monster comes with a cost
I really like the artworks of Impmon (and babies), Birdramon, Hououmon, RustTyranomon, MegaloGrowmon, Tailmon, Angewomon, Jyureimon, Milleniumon and Piemon
While the spike in price is also due to scalping (the practice of buying large quantities of popular or limited-edition products at retail price to reduce supply and increase demand), or the number of new people who only want to collect, if the card gets banned as a result of the skewed metagame, that value will likely drop, pissing off more than one dedicated collector
The matchup is rather rare nowadays but can be an unpleasant affair