Even minor imperfections, such as slight creases or scratches, can reduce the value of a card
I used to frequent TGW in Gaines Township for all my Magic: The Gathering cards, and these days, they still have all kinds of trading cards, including Pokmon cards
At this point, Doubling Season seems to combo with pretty much everything, but planeswalker superfriends decks love it in particular, allowing most walkers to ultimate on the turn they come down
Kurts Card Care Kit includes everything I use to clean, polish, and correct edge and corner issues
Its great for quick pickups, bulk lots, and cash sales without fees
Given the otherwise even footing shared between these cards, it's clear that Dialga's popularity makes it more desirable when all else is equal