You don't need a car in Thailand, it's warm every day.
So the comparison should be car in UK Vs scooter in Thailand.
Car 15kGBP Vs Scooter 1kGBP.
Petrol 1.5gbp Vs petrol 0.9gbp
10Km/ltr Vs 40Km/ltr
The room I rented in 2009 was 5000bht/month.
The same room is still for rent in 2022 for 5000bht/month.
Not that I have any worries about 2030+, doubt I'll still be here then.
I can't see why the price should suddenly increase, lots of empty rooms.
Man comes to Thailand, gets woman who wouldn't look at him in his home country, takes her back.
Same old story but with him returning rich, when everyone else returns broke.
All the 'rich' stuff sounds unlikely.
The Thai police would consider her taking drugs as consent.
Admission of taking drugs would probably get her 3-5 years in jail, so probably best she not shout about it too much.
If she owns the house, she will have a house book.
If it's rented to her, but she tells you it's hers, she won't have a house book.
Easy really.
There are no other possibilities.
House mortgage repayments Thailand = 9kbht.
Room rental in UK = 600gbp.
The pound would need to drop below 10bht = 1gbp before it would be too expensive for me to live in Thailand.
I would say simple common sense is to accept death when it comes, and not shovel money into the greedy hands of private hospitals.
As for the OP, walk away, it's not your problem.