Some cards have an improper exchange rate for cards that are visually identical but different in their set's rarity. Example: Poké Ball CPA 59 PHis a common card but requires 100 credits. It has an uncommon counterpart Poké Ball RCL 164 PH that costs 100 credits (normal) This is not applicable to every scenario though, as…
It appears that it happens when you have 59+ counts of a particular card, which would be plausible for commonly reprinted cards like potion, ultra ball, poke ball, etc.
