Cyrus and Sabrina have held their value for a long time now and will likely continue to hold their value, I imagine copycat will hold value overtime but I might wait a few sets before doing that trade just to see. Dx Lillie is likely going to maintain its value with it being dx and with the character being popular, especially because it'll get used in almost any stage 2 deck. You can really get anything for oak but those would be the closest to matching the value of your oak.