Double rare cards are, more or less, the same level of rarity as the Pokemon V, VSTAR, and VMAX cards that you may remember from the Pokemon TCG Sword & Shield sets
Shiny Pokmon always command a premium, but a Shiny Rayquaza is in a league of its own
Several factors influence Sword & Shield card values: card condition (mint cards worth 3-5x more), rarity (holographic and rare cards command higher prices), first edition status, PSA/BGS grading scores, and market demand for specific Pokemon
In enchantment removal, white was #1 and green was #2
No matter which combination of modes you choose, you always follow the instructions in the order they are written