My friend speaks English at FCE level and would like to prove that in her CV, but cannot afford to pay for a relevant exam. Are there ways she could certify her English knowledge that are less expensive than Cambridge exams?
I don't know if companies in whatever country she is looking for a job in require some formal certification. But here in the U.S., the best way to prove her knowledge of English on a CV (or resume as we call it) is to make sure that she uses good English on the CV itself! I've reviewed many CVs with very obviously poor English, like "I working the four years at company of General Motors" and that sort of thing, and while good communication skills are not the most important thing in my field (software development), it's a big plus, so good grammar on a CV always makes me mark someone up a point or two. I've been involved in hiring many people who are not native English speakers and I don't recall anyone ever asking for any certification -- we always relied on reading the resume and talking to the person. If she gets as far as an interview, then she'll have a real opportunity to prove her English skills or lack thereof.
As I say, I've only been involved in hiring IT people. If she is applying for jobs where language skill is what the job is all about -- like a translator or a public relations person -- the story might be different. And I can only speak for the U.S.