For dark types it's actually TrainDark
And...even if someone does list a sweet for 62,000 on auctions, the price will be increased by other players, so it will be raised to what it's worth.
You don't need money to play the sidequests😂. Have a good team that would 1 hit KO most 100 lvl pokes and have the patience to go through 2109 battles. You'll also get 1.2-1.4 mil pds along with other drop prizes on completing each region in the sidequests.