saying, "I'll have lots of time later to refactor my initial design, thereby asymptotically approaching acceptable performance and satisfaction of the important quality attributes"?
What shall we think when we hear a developer say, "But I don't have time to hold a code inspection"? Does the developer believe that he'll need the time he saves by skipping the inspection to fix the bugs that the testers find in his code? Odds are he'll need many more hours for debugging than if he had subjected his code to the scrutiny of some colleagues before unleashing the testers on it.
You may not think you have time to spend on process improvement, either, but we all want the benefits of improved productivity and quality that can come from changing the ways we work. One seminar audience complained that they were being asked to do more work with fewer people. When I asked what the organization was doing to enable this outcome, the reply was "Nothing." There's never a convenient time to take the actions that we believe will pay big dividends. But the inconvenience of later fixes generally comes back with a vengeance. All you're doing is passing the inconvenience along to the customer, and then back to your developers when the complaints roll in.
To save time and money, beef up your development and management practices, invest in thorough requirements development, iterate on your designs, and review your code. That is, do all those things that people erroneously argue take too much time. When someone is debating the importance of these quality activities, you can respond, "But we don't have time to cut corners."