That recruiter must have been pretty inexperienced to talk like that.
You should seriously question your compensation if a recruiter is willing to top you up 50k without a second thought. Chances are you are severely underpaid.
When you have another offer on the table the best move for the recruiter is to make the serious offer then and there and try take care of the situation to avoid any further bidding.
They want you for as cheap as they can get you but if someone else is willing to pay more then almost always they can afford it.
You should seriously question your compensation if a recruiter is willing to top you up 50k without a second thought. Chances are you are severely underpaid.