That doesnt mean some arent worth keeping an eye out for, though
Combat Celebrant is one of the cheapest cards on this list and a fairly easy way to get an additional combat phase
If you like the mana base how it is, other options for lowering this decks price can be big ticket cards like Cyclonic Rift and Elesh Norn, Mother of Machines
While just enchanting things for value is a fine, fun way to play Estrid, the Masked, things can get out of control quickly if you start playing cards like Overgrowth and Fertile Ground so that Estrid's +2 acts like a massive ramp spell, and then The Chain Veil (perhaps enchanted with a Mask aura thanks to Estrid's 1) give you an easy way to activate your Estrid, the Masked an infinite number of times, potentially making infinite mana by untapping your lands and eventually winning with her Replenish ultimate
Leaf is especially useful if you have an ex card in your active spot but can't afford for it to be potentially KO'd, as many of them have at least a two-retreat cost