I worked at a silicon company earlier in my career ... let me tell you, those defects get more expensive the later you find them by orders of magnitudes some times. That trend is true, regardless of numbers.
I wonder if there's any published evidence of this. I've heard the same thing and it /seems/ reasonable but then again it could be folklore. I guess it depends on the company and how expensive it is to fix.
I mean small or /agile/ companies that can repair a bug and deploy right away would have a substantially lower cost than say a large company that needs to have dozens of people approve something before it can be fixed.