He explains how adding a generically strong card that spikes a decks performance can be a bad thing, as it makes the deck less consistent, not more consistent, and it leads to opponents feeling like they need to bring stronger decks that will dominate your decks true average performance
If you have ever browsed a pokemon mega evolution card list and noticed how many entries belong to Mewtwo, that catalog speaks directly to how central Mewtwo is to the Mega Evolution concept
That sounds good enough, but its probably not great
(Source: Cardmarket 15.02.2024) Now as you can see there are roughly 20 cards on Cardmarket that will fetch a price over 100 Euros, especially if they are in Good to Near Mint conditions
This is most likely because, due to being full artwork cards, they already get a shiny little introduction when you place them on the field in a match