The issue here has almost nothing to do with supply and demand (albeit it has an implicit effect on that stated). The issue here *is* the fact that in order to sell software in this day in age, you must be producing software with an edge. That is, if you are creating an algorithm, make sure that your algorithm cannot be copied or reproduced by a college student. Your product is not worth my money to buy the product if this is true. I give Google and Microsoft as examples. Open-source is a very volatile field, software as well. Let's just put it this way, if you are thriving on extensions and profits of those extensions (at the same time failing to gain profits), then you need to move on to another strategy. Nobody will by the product is they know there is a better free version around, so you must either make a version that is faster and better than the free version or get out of the market.