Hmm, tricky. I could post some execution times. But I doubt that the exact ratio "debug with a breakpoint set" / "debug without a breakpoint set" actually adds much information.

What is of interest is that the breakpoint isn't being hit. It's not a conditional breakpoint inside a loop for example. In the immediate case it is a breakpoint set to let me inspect variables after a lot of work has been done (parsing a 1 Mb file with HTML::TreeBuilder).