If you don't have user-testing as an integral part of your design process you are going to throw buckets of money down the drain. How user testing saves money Problems are fixed before the product is shipped, not after. Every company user-tests. For some, it is done as an integral part of the early prototyping process. Others do it during beta.
Most companies still do it post-release.
It is far less expensive to have one person spend an hour revamping a light-weight prototype than for a room full of customer support people to spend two months fending off calls while your entire engineering team tries frantically to fix reported problems and get out release 1.1. The team can concentrate on real problems, not imaginary ones. This is perhaps the greatest money-saver. Developers know about most of the problems that will be found before the testing even begins. And they have no tool other than testing to tell the difference.