I think Bernadette and Bette are in different leagues money-wise. While Peters' salary was in the $50,000+ category (I believe she got a percentage of the gross whenever attendance hit certain percentage levels ), Midler had one of the top grossing concert tours in the country last year (she took in over $ 1 million per week for much of the past two years -- though she wasn't out every month).
But, money's not the issue with Midler (especially since she now has more than she could ever spend in ten lifetimes). While she's said in interviews that she might be interested in coming back to Broadway in a real musical at some point, I get the sense (though she's never said it) that the grind and rigors of eight shows a week might be more than she wants to put herself through at this point (with her concert tours, she's usually only doing a few concerts in a week and she never has two show days).
It's totally up to her. She could come back in any show she wants to. Heck, if she wanted to do a revival of "Panama Hattie" or "Coco" or "Destry Rides Again" producers would fall all over themselves to put money into it to make sure that it happened.
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney