How about second wind in Starfinder?

SECOND WIND (COMBAT)

You take a quick breather, and you are back in the fight!

Prerequisites: Diehard, character level 5th.

Benefit: Once per day as a swift action, You can spend 1 RP to roll a number of dice d8s equal to your hit dice and immediately regain that many stamina points.

Thoughts? I debate among myself if this should cost 1 or 2 RP.