Unlike investments in technology, usability is based on human psychology and user research. If you understand humans via research, then building the right product, service, or web site, is basically guaranteed. I'm not kidding. Well, don't take my word for it, take a look and come back with smile. Usability is not a joke.
Usability is about hard core profits.
Do the testing. Do the research and gather the data. If you don't have the internal resources, outsource it, especially in down times. The benefits are basically guaranteed. Unless you think you have a truly customer focused product or web site, then you will gain from usability research.