This info is actually very useful for me as it confirms my (rational) fear of accumulating expenses. It's way too easy to just spend $10-$50 here and there and before you know it you are spending $1000 a month, while the core service is still running on a single triad of web-server/worker-server/database-server combo with no redundancy. On the other hand it probably contains everything I could think of and it's still…
I literally use none of any such paid services. Zero. It's really not that hard. Just automate what can be automated.
I use a service that sends me a bunch of fairly trivial Google Analytics data. It costs $10/month for the equivalent of fifty lines of Python.
I know I could spend maybe two hours writing a replacement for it and set it on an EC2 host and probably never worry about it again, but those two hours are still non-trivial amounts of time: two hours of my time pays for more than three years of that $10/month. Plus, the API may be brittle, there may be edge cases I haven't thought about, and I don't want to add yet another thing to monitor and worry about.
Sometimes, yeah, you can automate things and roll your own dependencies -- and sometimes the calculus works out and it's a no-brainer. But I've found that homebrewing a $XX/mo dependency is rarely the best use of my engineering time.