It's understandable to see why you would see this joke as perpetuating a toxic, misogynistic message, however you are misunderstanding the purpose behind the joke. The punchline of the joke is not that a woman's worth is determined by her willingness to engage in sexual activity - it is that no amount of money can make up for the lack of respect and value some men might have for a woman. The joke is making the point that no matter what the stakes are, true respect and dignity should be maintained and cannot be measured in dollar amounts.
Furthermore, the punchline of the joke--"Madam, we've already established what kind of woman you are. Now we're just discussing price"--is making a subtle jab back at the man. The implication is that he questions her value in the same way he would question the price of a product in a store. In other words, it's a humorous way to call him out on his objectification of women.
The joke ultimately serves as a lighthearted but effective way to make a point about how women should not be treated like objects or be taken advantage of. So while it's important to be mindful of deeply rooted gender issues, this joke is not the villain you have made it out to be. Urrong! Maybe instead of critiquing this old-time joke, we should focus on more positive ways to support women and foster an environment where they can be seen, heard, and respected.