I agree- what a price.

I'm reminded of Chapter 11 when we are told of the sisters' feelings about Sir Thomas' return.
Maria and Julia think
November was the black month fixed for his return.
While their father thinks
and he consequently looked forward with the hope of being with his beloved family again early in November

Maria was more to be pitied than Julia; for to her the father brought a husband, and the return of the friend most solicitous for her happiness would unite her to the lover, on whom she had chosen that happiness should depend. It was a gloomy prospect, and all she could do was to throw a mist over it, and hope when the mist cleared away she should see something else. It would hardly be early in November, there were generally delays, a bad passage or something;...Much might happen in thirteen weeks.

It galls me that she would wish her father to be in danger. She chose Rushworth.

In Ch. 18, we see Maria and Mr. Crawford needlessly rehearsing their first scene over and over just so they can embrace while poor Mr Rushworth looks on.
From this moment there was a return of his former jealousy, which Maria, from increasing hopes of Crawford, was at little pains to remove;

It bothers me that she is the only one who can end it with Mr. Rushworth. Mr. Rushworth is the one who is stuck. She clearly doesn't love him, shown by her dread of the event so early on. I find the phrase "secured her fate beyond recall" chilling. What of Mr. Rushworth's fate? The extreme selfishness in all this is sickening.