[throwawaycert]

It's not that weird. If your score is, say, 750, 50 points is about a 7 percent change. My finances very easily vary 7% from month to month!

50 points also isn't likely to make much difference, especially if your score is already good. Loans basically go off tables. Essentially if you're between A and B, you get this rate for this losan, C and D gets this rate, etc.

Once you're past 700, you're already getting good interest rates and banks will fall over themselves to loan you money if your income supports the loan size. When I was at 780, the loan officer couldn't give me a lower rate on a mortgage - I was already getting a fraction of a percent over prime.