You may find you run face first into human nature at that point. After all, how many people are going to play "basic" DnD compared to how many are going to say "I'm smart, I can play Advanced Mode"?
Also, two versions in print can be an absolutely terrible idea, compared to one version with a few different ways to scale the difficulty, because two versions is twice as expensive to make (just in terms of printing costs) but you are likely only getting the same amount of profit. So, it could be a really dangerous proposal that I don't think is needed. The core game being best suited for less experienced players is fine, because more expierenced players are also more likely to have rules beyond the core.