Chimney Overhaul Costs

I looked at a house today with a fireplace/chimney in need of work. Maybe someone can help me with a ballpark figure for my preliminary cost calc.

The brick fireplace had several bricks above the opening that were toppling inward. These were above the insert. The residents were using the fireplace when I was there, incidentally. From the outside I could see a vertical crack along the entire 8 inches or so that the insert was exposed at the top.

So minimum I’m looking at major repairs. Another option might be to get rid of it. I could replace it with a wood or pellet stove which are popular in the area.

Anyone dealt with major chimney repairs?

Thanks,

Mike