Phelia, Exuberant Shepherd and Ephemerate are the gold standard for blink cards currently, and Airbender Ascension is slower than both
There was an operation selling high value foil counterfeits, done by high quality laser printing on original (cleaned) cards, but those failed a simple loupe check as they had no real rosette pattern at all
Not background necessarily, but some other line of text that says something along the lines of Whenever you sacrifice a Treasure token, give a creature a +1/+1 counter and trample until end of turn. That would make it a lot more interesting and powerful, but I suppose not every card needs to be great
Other Marketplaces To get lower than around $90 will take some searching and a bit of timing
As I frequently do with any new set, I started browsing the new, exciting, and most valuable cards from the Edge of Eternities
Mint cards are not perfect, but they have sharp corners and good centering