I saved FB and me time by telling them up front in the phone screen what my comp would have to be. They acknowledged the scale for the position would never be that high. I find it absolutely insulting that FB and other desirable companies think they can lowball someone just because they are not from one of the big companies.
In all seriousness, you can quote a high number and throw them a bone. At the same time, let the recruiter know that you want to know their numbers and that you're hopeful on reaching a number agreeable for both sides. This shows your willingness to accept a certain offer without giving up your own side.
Having competitive offers always gives you leverage and you know have to worry about them pulling out.