Is it true that everyone has a price?

I keep hearing people say everyone has a price. Meaning there's an amount of money or reward someone will be willing to do something for.I was watching a video in which females were asked if they would sleep with a professor for a better grade. A surprising amount said yes depending on the teacher. It seems like nowadays a lot of people would anything or anyone for money or status.I'm not looking down on these people, at the end of day everyone has the right to do what they want. I just feel like self worth is really low these days. I've seen first hand what some people are willing do for money and to me it's just sad. I just feel like people should not let others take advantage of them, especially women. I see a lot of times in 3rd world countries where rich guys visit and take advantage of the local women. Because a lot of them are in need of money just to survive, I know under normal circumstances they wouldn't do such things but sometimes to survive they have to. It really breaks my heart.