How much is a middle-age woman worth?

How about this.......
A middle-aged woman has the chance to dump her horrible boring life- live in Kelowna (well without the fires!) on top of a mountain in a multi-million dollar house..... the guest house is another multi-million dollar shack at the lake complete with one boat at the dock (the big boat is kept at the Yacht club as it is too big for this dock) complete with swimming pool. The guest house is by the lake and main house is on top of the mountain because the traffic and noise of the lake annoy the owner!
There are actually 3 boats, a million dollar motor home used to travel to Palm Springs 'condo' .... many cars but the ones mostly used are always brand new Mercedes "really the only people that buy Lexus are those that can't afford Mercedes".
The catch- he is almost as old as the lady's grandmother- so late 70's- early 80's. Very rich, has known her for over 20 years and truly likes her, she truly likes him- Just not in that way!
Other kicker ---- He does not pay well when he is bored of his women!
No cars in her name to take, no houses in her name to take-even the jewellery he buys (BIG- HUGE stuff) he insists are for investment and 'lets' her wear them- but they are not hers'.
Last one was with for 12 years and walked out with $100,000 and after a court case the 5 carat ring... after a court case. No support, no car and no house!
I told him he did well- really well!
Glad I was not the girl that quit my job- no matter how low paying it may of been and ran around the world with him to end up 47 (with good plastic surgery, great nails and personal trained body) but now single, basically no money, no marketable skills (Shhhh- other then the obvious) .
So, this is one of my dearest friends- the guy actually----- I suggested in the future he has 'a lease' on the women, sign it and carry on!
What do you guys think--- Him and I went through this and my 'price' was way to high for him- so I guess I can be bought--- but at least I have some respect- if I am going down the wrong road I at least am expensive-- needless to say- He is still single!
So him and I are wondering - what is a fair market value for a middle-aged woman to live the life of luxury---clothes, borrowed jewels, borrowed cars, borrowed affection, girl must cook, the houses do have cleaning staff though---give up any job she has to care for him) How much is that worth? How much should be left in the will? What about a signing bonus and yearly 'cheques' for work well done?
Any ideas on how and what should be examined in this?
Truly we are wondering....... He has his opinion and I have mine- obviously not the same!