Good Smile Company now has a third Overwatch Nendoroid to go along with those cute lil' Meis and Tracers: this very smug Mercy.
It's out in January 2018, and will cost around $50 USD.
You can pre-order it here: http://www.crunchyroll.com/store/p/197771/Mercy-Nendoroid-Classic-Skin-Ver-Overwatch