Do we know what Heiresses were worth?
The real problem with the valuations of people's estates in past centuries is that the estates were never included in the valuation.
As far as I can make out the theory of feudal land-holdings was that the land was the sovereign's and the landowner was merely a tenant who took the rents and provided services, knights or money in lieu, to the sovereign. So what was known was the rental value of an estate, not its worth.
The estates were inherited by the eldest son, or if no sons, divided between all the daughters and, if no daughters or other discernible heirs, reverted to the sovereign. Certainly in the first half of the middle ages it was difficult to pass landed property from one person to another. These days such transactions are called sales, but then they were called "alienation" and were difficult to achieve. Certainly alienation could only be achieved during one's lifetime, not by will.
Hence wills were only about transferable property, beds, silver, coaches, horses, clothing, jewellery. While these had known values, they were but a small proportion of what we would describe as the total value of an estate.
To some extent the omission of land from wills and from the valuation of estates continued until the end of the 19th century.
So, we do not know what, in the days where landholding was the major source of wealth, heiresses to landed estates were worth. We can only make guesses on some multiplier of the rental values.