I dont like to say never when working on a trading card game, but here I go: Well never do a promo card or collection that you cant also get out of the regular product, Miller tells IGN
(You could argue Brilliant Stars is the more over-all valuable set, given the number of over $20 cards in there, but even its alt-art Charizard V doesnt quite scrape the $200 mark.) These are, of course, their ungraded prices, with numbers vastly increased if sent of to companies like PSA to receive a grade, especially if they can achieve that all-conquering PSA 10
You can search by specific card, for example, if we want to look for things to do with Mindslaver or if you're really devilish, you can search by combo type, such as Gain control of all of target player's turns. Highly recommended
Cheap binders with side-loading pages
(You may cast a card from your graveyard for its Mayhem cost if you discarded it this turn
The payoff for Etali can be enormous, but its incredibly fragile for a six-drop with the available removal in the format, so unfortunately we may not see much from this elder Dinosaur