It's definitely a botters' account, cards were transferred, not bought. Thankfully this account doesn't have GF cards, I'm trying to find these, maybe I'll find a trail. This account does however have rare and common cards that can be burned for (at least part of) the necessary DEC for staking on land.
The main question is, how many other botting accounts are there that hold large amounts of cards (also lesser cards) and is there a risk they will exploit "land surfing".