I am at the onsite stage at FB and can push that back as much as needed. I am also in the middle of interviewing at Google (which takes ~2 months) and just started interviewing at Twitter and a couple other companies (that take ~1 month). Purely just to up my TC.
I am concerned about opportunity cost. I have two options: be unemployed for 1+ months and get a slightly larger salary at Facebook, or accept a smaller salary now and start working sooner. Advice?
Of course, if you are unemployed but financially stable and can wait 3-6 months then you can hold out for the highest TC and see what happens. But unemployed without a lot of savings, take the job now.
Good luck!
And even when you have the offer on the table, since you already started the process, I would probably follow through with them in any case.
You are in a much better position if you have competing offers. This is what allows you to negotiate, and leave the company quickly if you don't like it.