Considering that both cards are in print and, discounting the Aftermath debacle, is from Magic's newest set, I'd lean towards selling while prices are high unless you plan on building the deck yourself
BREAKpoint Investment Guide Navigating the Waters of XY's BREAKpoint Set Released in early 2016, the BREAKpoint set of the Pokmon Trading Card Game offers a unique blend of popular Pokmon and dynamic artwork
Ponyta can start attacking with only one Energy, but unlike the one found in Genetic Apex, it has the potential to hit for 40 with a good coin flip
Taborax, Hopes Demise Taborax, Hope's Demise is a demon cleric that cares about your creature deaths
Finally, Cast Down is an instant costing 1B, capable of destroying any non-legendary creature on command.
Set Code: OP08 Click on any card to see more graded card prices , historic prices, and past sales