It doesn't take an idiot to realize that this business model doesn't scale well into a sustainable business. If it was such a good idea, we would all be doing it, including yourself. I don't have the time to buy, manage, sell 1 domain for $3 profit (100% profit on a $2.99 coupon), and do that repeatedly. How much time and effort does it take to find one of these domains? 1hr, 2hrs? Lets say you sell 1 domain each an every day. It's not a workable business model. Now if you make 10,000% profit, a meagre $300 sale, it begins to make some sense. But at that level, there are far fewer domains available for reg-fee and worth $300, and even if you find one, how long is it going to take to sell it? Not in 1 day, maybe not in a month, maybe never. Probably you won't be able to sell it here on NamePros. So now you have the lengthy process of identifying potential end-users and actually selling them a domain, they had no idea they wanted. Suddenly your 100% successful quick sale, has shot down to maybe 10%, tops. Your profit $297 minus the $27 you spent on the 9 domains which didn't sell, is still a good profit. But if it takes you lets say 4 hours to find and sell (or not) each domain, and you only sell 1 domain, you have spend 40 hours (a weeks work every day) for that $270 profit. Then you are back to a non-sustainable business. I don't see any method of calculation which makes this a sustainable business model.
Please supply the numbers which explain how you think this is a doable and sustainable business model.