Tourist vias

Hi, I live in Los Angeles, like to obtain a Vietnam Visa. I will travel to your country from 03/12/17 to 03/22/17. We were asked not to get the visa on arrival, so I need to apply it before I go. I am bit confused with your fee table. Can you tell me how much the visa fee is? Can I mail the application form to San Francisco or have to be to Washington?
Hope to hear from you soon, thank you.

Jane