After reading hundreds of thousands of posts(...and that is just The Orc King...LOL) on this and other sites, people need to have more patience. Time is your friend, but many people think week to week, month to month. Many of you already know how I feel about short term flipping...I really don't recommend it. Why? Because as many have mentioned above, flipping sets for many members equates to a minimum wage type of job. Now don't get me wrong, you can make money short term flipping sets, but how much money for the time invested is the real question. There are some exceptional sets at times that can be flipped for a solid profit, but they are the minority.
This is also not a knock on small sets. I just bought 20 smallish sets from Amazon and Target two days ago, so I am a believer in small sets. But you need to market small sets properly to get the best bang for your investment buck. Flipping $15 sets one at a time is a waste of time IMO. You are better off coming up with creative combinations of sets(lots) that might entice a buyer, which reduces commissions slightly and saves time on shipping and packaging.
Back to my original point, expectations are too high given the time frame in which many work with. LEGO investing is not a 2 or 3 month process. It can take years. People getting involved need to invest money that they "don't need to live off of." If you need to short term flip sets to make rent payments, you will be homeless soon enough. Do some people pay their rents/mortgages off of LEGO reselling...yes, I'm positive there are some that live off of that money, but the vast majority of resellers cannot make enough to support themselves. The exceptions might have a true knack or insight to picking the proper sets or connections to locate cheap products. If you get involved with LEGO investing with eyes wide open and some spare cash, space and time, you can make some decent money. Otherwise, it's a a lot of work for a little money.