I try to watch the show as often as possible. The girl with the Range-Rover is Ava. Her party was about $200, 000 (that's with the Range Rover included). The theme of her party was "Arabian Night" with her being treated like a princes, carried by like 16 college-aged guys (too old for her).
The one that had a $500,000 party had a father who owned about five nightclubs in Southern Cali. You should have seen the cars he owned: damn. You know why she spent all this money? She wanted to become the most popular girl in school because she was new to the area. She didn't even know most of the kids that were at the party. That's great: spend half-a-million to impress fellow peers.