Unfortunately there are markets where drop-shipping just can't compete, that's the nature of the business. Of course what tends to happen is that most people want to use a drop-shipping model to compete in those exact markets because they are the extremely high turnover hot selling markets.
What people don't realize is that those types of markets are dominated by big wholesale buyers and even wholesale suppliers themselves selling on very thin margins to great market saturation and make their profit through high turnover.
There are drop-shipping markets on sites like Amazon and eBay, but you have to look outside of the big markets where there aren't the huge turnover rates due to the much lower customer demands. Those are the markets where big wholesale sellers and suppliers aren't, which then gives opportunities for drop-shipping.
So it's about being realistic more than anything, you have to pick your market very carefully to give yourself the best possible opportunity ....... especially when using a drop-shipping model.