Adding features adds complexity. Features interact with each other in complex ways. If you add a feature and don't know quickly if it broke another feature, that costs time.
Letting the users find the bugs costs time - you have to talk to the user, replicate the bug report, find the failure, fix it, and then release. Finding that same bug 2 minutes after you wrote it (and before it got released) is massively quicker.
This feels like one of those "write code 16 hours a day to make more progress!" things that experience has taught me just doesn't work in practice. I feel like I'm making a lot of progress, but after about 10 hours most of the code I write is pure shite and needs to be rewritten the next day. I've found that it's actually way faster to quit coding after 8-10 hours rather than spend 2 hours the next day rewriting everything I wrote in the last 6 hours the day before.
Tests cost money up front. Can you pay for those tests? You said you will pay for it in decreased costs once the business is running well.
Ok but how confident are you that your business will work out?
1%? you just increased your project costs 100 fold by doing tests.
50%? you just doubled your project costs by doing tests.
100%? Ok you are saving money, but if you are that confident then why haven't you gotten investors aboard that are convinced that doing it well from the start is a business edge?
Letting the users find the bugs costs time - you have to talk to the user, replicate the bug report, find the failure, fix it, and then release. Finding that same bug 2 minutes after you wrote it (and before it got released) is massively quicker.
This feels like one of those "write code 16 hours a day to make more progress!" things that experience has taught me just doesn't work in practice. I feel like I'm making a lot of progress, but after about 10 hours most of the code I write is pure shite and needs to be rewritten the next day. I've found that it's actually way faster to quit coding after 8-10 hours rather than spend 2 hours the next day rewriting everything I wrote in the last 6 hours the day before.