There is no wise choice to be made.
People can change completely in very short spaces of time.
Best not to base your future on the grace and favour of another person.
I'm buying a house for my woman, costs me 10kbht/month, about the same as I would spend in rent.
By the time I'm 90, the house will be hers, no hard feelings from me if she wants me out before or after that time.
No further legal obligation to her on my part.