AE projects can and do sell very well... but it depends what it is. Simple can be good, but if it's quicker and easier to do it yourself then nobody will buy it. And if it's too simple, then it might not get accepted by the marketplace in question. If it's simple but it saves somebody a lot of time, then that could work.
I've seen one AE template that makes the guy $20K a month, which is not too shabby, so there's definitely opportunities there... but there's plenty that might only make $2 a month!