Feedback appreciated..
1. Have you tried every other solution to know for a fact that it is simpler than all of them?
2. Simplicity and ease of use are very subjective. Many people might find Basecamp easier to use than your PM.
Before diving into something like this, you should make a very solid list of features you want in your PM tool, and a list of features you don't want. Then do research to compare it to others on the market.
While I think there is still market space for more project management tools since every individual and team have different workflows, most PMs I have experimented with have largely the same features. That means they have all the same pitfalls.
That being said, "cheaper than existing solutions" is also not what you should base your plans on. There are dozens of free solutions out there, many of which are very popular. It doesn't get much cheaper than free.
Answering "no" to any of these things should make you think twice about attacking the problem for profit. Answering "yes" to them all might indicate you should build a minimum viable product that solves the problems you know about in the simplest fashion possible, then you can try this out on some friends or acquaintances who could benefit.
Keep in mind that people invested in BaseCamp will probably not find it easier to use at first, and unless it's a knockoff, it will always feel like it is missing features for many of those people.
I think it is more of matter of target market than anything else, and web entrepreneurs and programmers will be a harder market to penetrate than general small business.
I tried basecamp and failed.