Cost to open up existing closet

What would it cost to open up existing bedroom closet that currently has only one door. It's difficult to reach clothes at the back. The same closet in master bedroom has two doors, opening in the middle, and can be opened wide for ease of access. We could use the matching linen closet door with matching handle and replace that door.

This bedroom closet is 2 door widths but with only one door, making full access to clothes in the back of the closet very awkward. Would require cutting out part of bedroom wall, adding a second door to close in middle. Matching door from linen closet, with matching glass handle, would be ideal to maintain the look of this 80-year old house. Therefore need to replace linen closet door with a new door. Closet in adjoining master bedroom is same size, but with 2 doors.

An estimate would be appreciated. Also, how long should it take?

Thank you for advice.