How would you deal with a client trying to drive down your price?

I got this email from my client today:

Hi xxx, Is $150/person really the lowest you can go? If you can’t go any lower we will have to use someone else. $750 + tax seems very steep for 5 headshots. Please let me know, Thanks

I'm not that busy these days, but I do have a lot of experience and I'm really good at what I do. Of course people offer a similar product at a cheaper price, but they don't have my gear nor my experience. It seems like my client just wants to the cheapest service possible. Should I take the money and just do it? Or do you think I'm better off using my time to do something else?