175, 000 dollars isn't a lot of money.
So Nancy's step father dies and they get 175,000 dollars and they buy an pretty large apartment on a high floor with a pretty amazing view of the city. Along with that Nancy buys a red convertible.
Even in 1996 their money would be totally gone after that. Very stupid investment.
What should have happened is they find a pretty reasonable priced house and a inexpensive car.
This part of the movie bugs the hell out of me. But I guess it makes sense since Nancy is completely insane.