I copped this version of the Hidetsugu you're thinking of for $30 at my LGS a few weeks ago: https://scryfall.com/card/neo/432/hidetsugu-devouring-chaos

Prices of swaggy stuff is always irrational until the smallest attention spans have moved on.

I assume you know about Collector Packs, those are my favorites for splashing a chunk of money on a set. If I can afford to preorder a box, or pick one up on some random sale, they have the highest swag tier.

The only card I've sold in the past several years has been a copy of Parallel Lives. It got me enough store credit to cop a Chatterfang, and some other goodies to build a first Commander deck after not touching my cards in years. I had 4 or 5 copies, so it was easy to part with. I also gave one copy away to a friend who had just bought some sort of 'Hobbits and food tokens' precon deck.