We don't have time to write tests, we'll lose opportunities

There's the common misconception that if you write tests you'll be wasting time, time that you could spend on fixing bugs and creating features. Either that or your spending a lot of time and money on tests and not enough time on actual features. This is a false dichotomy.

The reality is that you are already doing testing, but in a MUCH more inefficient way: manual testing. The larger an application grows the more complex the interactions become, which means the multitude of combinations of interactions grows. Having to remember and perform those combinations of interactions gets time consuming up to the point that they're disregarded in order to push out features and "fixed" bugs. What happens is that bugs get introduced into production or more time is spent on features because of the manual testing to ensure there aren't any bugs.

It is true that poorly written tests will waste time, but properly written tests will save time to find problems that most-likely wouldn't have been discovered through manual testing. That means a more stable software product and happier users. It's known that users get frustrated when they aren't able to accomplish tasks that are supposed to work in your application. The more they're frustrated, the more they'll leave. Are you willing to lose users?

Writing tests for your code shouldn't be looked at as wasted time. That code is there to ensure bugs aren't introduced to your live application. It's there to prevent problems before they happen. If your developers spend "too much time" to try failing tests to pass, imagine if the tests didn't exist. Would they have been able to see how the changes in their code broke functionality in different areas? Possibly through manual testing, but with a lot more effort.

Stable software is easier to achieve by writing tests.