Well, we’ve already seen that magic, once done, is often easier to repeat–Zelena was the first ever to create a time travel spell that worked, but Emma could repeat it with the Black Fairy’s Wand simply by having been through the portal. They’ve actually discussed an evolution of the sleeping curse over time.
So creating the curse once was probably a LOT harder than recreating it later. Or using it the way Pan did. (They still cheated by letting Charming live…not that I want him gone or that I didn’t like the one heart business, but it was still a cheat.)
Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing