Though not directly related to equipment, ability doublers are an excellent payoff for these cards as the best equipment are often those with strong triggered abilities, like Skullclamp and the Swords
These include the much talked about Black Lotus (the most valuable card) plus Ancestral Recall, Time Walk, Timetwister, and the five Mox cards (Mox Pearl, Mox Sapphire, Mox Jet, Mox Ruby, and Mox Emerald)
Right now, Oko is below $60 after topping out around $67
Unlike the Umbreon artwork, Celebi Gold Star was never reprinted for the 2021 25th Anniversary Celebrations set
Milling your opponent is actually positive for them unless you can finish them off, and there simply isnt enough lifegain to enable Hope as a potential win condition