Does anyone know how much a battery for a mid-2012 MacBook pro cost?

Here is the US service pricing:

Mac Repair - Official Apple Support

The 13-inch Mid 2012 MacBook Pro is still a "supported" model so Apple can replace it. My son just had his 2012-13" done. The cost quoted includes labor. If there are no open Apple Stores near you, contact Apple support about mail-/ship-in service.

CaioM007 wrote:

Does anyone know how much a battery for a mid-2012 MacBook pro cost?

About $90. See: https://eshop.macsales.com/shop/laptop-batteries/macbook-pro

Hello,

You will need to call Apple for assistance.

Contact AppleCare