Well, I'd pay, say, $10 a month for a service that was simple, offered some retry algorithms, logged responses, gave me a nice UI for the whole thing and worked

Well, I'd pay, say, $10 a month for a service that was simple, offered some retry algorithms, logged responses, gave me a nice UI for the whole thing and worked reliably (unlike dynos on Heroku, which are nuked regularly.) Not rocket science, to be sure, but I'd rather not build and maintain the infrastructure. Or I'd rather build and maintain only that infrastructure.