Agreed. Actually the question does still hold interest IMO because it forces her to acknowledge to herself that she may have a price.

You say:

In reality, most people have made that choice long ago and we know that they have their consequentialist price.

And I agree; however I wonder how many people consciously know what their "price" decision they have made.

I once actually conducted this experiment with a group of [volunteer] fellow students (both male and female) with interesting results. I pitched the question exactly as outlined here (a girlfriend asked the male members). The aim was to force this self-realisation of their "price" and subsequently we "bartered" for the real price they would accept.

I realised a couple of things; firstly in realistic terms 1 million pounds is generally a lot lower than the "realistic price". When I followed up with the question "would you really sleep with me for a million" the answer was usually "no". The reason the girl says "maybe" in the initial instance is because she doesn't believe that I have a million pounds to offer.

When I substituted £100,000 for a million the response rate tipped much harder towards "unlikely". To further test this theory I asked one of my more well of friends (who looked stereotypically rich) to conduct a similar survey - but this time to show them a cheque made of for £1 Million at the same time. Again the responses tended towards "unlikely" (and there was, actually, a larger amount of disgust at the idea).

Once I got past this stage we bartered on what the "price" might be; invariably money was quickly removed from the table. Favours were preferred; for example attending as a date to a wedding was one price. When I forced conversations back to money the price went a lot higher. £10 Million was the minimum (this is possibly because 1 Million is not considered so much any more, I don't know). My well off friend had even more dramatic rises; one girl requested £5 Million a year for the next three years.

More sex was generally offered in return for more complex rewards; for example in the above example (£5,000,0000/yr for 3 yrs) it was hashed out that a number of sexual encounters and "weekend breaks" were on the cards.

For the men things were a lot simpler; they balked at any ides of being paid full stop. Almost to the man they refused payment and offered to sleep with the girl anyway. Out of interest I got a much plainer girl to ask the same question; there was still a general refusal to take money (although one or two "accepted" £100, preferring it to 1 Million) but also several outright refusals. With the plainer girl men offered to sleep with her (for no money), for my more attractive friend they offered to sleep with her and take her out to dinner.

In fact dinner featured a lot in negotiations; there was actually a general aversion amongst the men (particularly, for some interesting reason, among the "jock" types) to simply having sex, a big majority preferred to offer a more complete "package". I have a partial theory that some were sidestepping the issue of money by proposing that the girl paid for dinner (or whatever date was agreed).

This was conducted on a group of about 100 people I randomly grabbed outside our student union over a couple of afternoons :) there isn't a lot of structure to what we did, we just followed our noses. But I think there was some interesting stuff we discovered.