"She had expensive tastes" normally means a person who spends money on expensive clothes, jewelry, and trips. "She was expensive" is different and has multiple possible meanings. 1 - An expensive prostitute. 2 - An expensive girlfriend (a girlfriend who expects to be treated to expensive dinners and trips). 3 - A talented professional who can charge very high fees because of their skill and reputation. Here are examples of #3. She was a mafia killer. ... businesslike, cool, and very expensive. She was a famous lawyer. ... businesslike, cool, and very expensive.

A bit more context is needed here, I think. I assume this is a description from a book/novel? You wouldn't normally say someone is expensive. If it is creative writing, my guess is the narrator is describing a woman that he is dating and that she likes to be bought a lot of expensive gifts and taken out to nice, expensive, restaurants. That sort of thing. It costs him a lot of money to be with her.

I would also agree that a little more context is needed about the character but my closest guess without it is when we used the term "to have expensive taste". This means that someone only likes things that have a high price, from the type of restaurant they dine in to the kind of clothes they buy etc.

Correction - Ah, OK. This is from Cakes and Ale by Somerset Maugham, and it refers to a very expensive cook. My mistake :) Although the book does go on to say that she does her shopping in Shepherd Market - which is a district of London with a particular reputation. The writer is flirting with multiple meanings. This is from https://en.wikipedia.org/wiki/Shepherd_Market ( See also https://riddlemagazine.com/the-mayfair-beatnik-2/ ) "It [Shepherd Market] was associated with upmarket prostitutes from its building up until at least the 1980s.[2] In the 1920s, it hosted leading writers and artists such as Anthony Powell, Michael Arlen and Sophie Fedorovitch. Jeffrey Archer here met Monica Coghlan[a] in the 1980s.[1]" It suggests she is a prostitute - an expensive one. The kindest interpretation would be that she has a lot of money and only wants to associate with rich people.

The word expensive in this context expresses HER (self worth) Pronounced (ɪkˈspensɪv) = Expensive is about the how great/costing the amount is I hope this helps