cards like sneak attack mtg #145 Holo from Double Masters (2XM) Proxy That creature gains haste Sneak Attack | Eternal Masters

You could just use this as a sac outlet that nets Treasures, but my mind goes immediately to Gravecrawler and any third combo piece you can think of

Each of those (Golem, token, power 3) are solid subthemes to leverage for additional, unique advantages

Each of the Power Nine cards is alone worth significant money - albeit not quite as much as their earlier Alpha and Beta set counterparts - with an Unlimited Black Lotus fetching up to $22,750 according to price tracking site MTGGoldfish

For cards to make an impact, they will either need to bring something new to the table or just be an all-around powerful card

Chrome Mox, Mana Crypt, Sol Ring, and Arcane Signet make up all of the rocks in the list