There's also the potential that the offer gets pulled because they realize you're not a good fit based on the large salary range discrepancy. If I'm hiring for someone at $50K and they're asking for $150K, I know that there's a good chance the employee will end up being unhappy financially and looking for another job anyway if we compromise closer to $75K.
You never know for sure, but I believe this happened to me. I had a follow up call with HR about why they weren't continuing with me despite what felt like a good "getting to know you" introduction interview.
The gist of the answer was "we feel that you are in range of [some job level/position] but only the very senior people in that department are paid in the range you mentioned as your requirement."
So they decided not to spend any more time with me because of the mismatch of salary and their perception of my experience level so far.
For example, if you are negotiating your salary for a first-time software engineering gig and open with $500k, the other side is likely to say something like, "There is absolutely no way we can do that. We would like to offer you $75k." If you're offer gets wiped off the table, your anchor has absolutely no power in the negotiation.
So go high (or low, if you're on the other side of the table), but don't be too extreme.