If it was that easy, everyone would do it. There are several significant hurdles to your plan.
Drop shipping is not as easy as calling up a manufacturer and saying, "hey Bose, yeah, this is Joe Blow... I need you to start drop shipping your noise canceling headphones for me.... Yes, that's right, you do all the work and I'll send you a small number of customers." Remember, manufacturers are businesses too. They don't want to invest the time, energy, and manpower drop shipping takes unless its worth their while and, most of the time, it isn't worth their while for a small-time guy. Even if they already run a drop-shipping operation, adding another customer has expenses! In my experience, if a company is willing to drop ship, they will want some sort of deposit or security up-front from you and they often have minimum volume requirements. Are you ready to meet those requirements?
Even if you do find a company willing to work with you, your problems have just begun. You now need to vet them. Are they reliable? Are they located overseas? Do they make a quality product? Is there product potentially dangerous or harmful? If they're overseas, you could be left holding the bag if a customer sues you. Even if they're domestic, you could be caught holding the proverbial bag of shit. Just look at all the Chinese-made junk that has killed people in this country and now imagine you're left dealing with a victim's family suing you because you distributed your bogus widget that got their daughter killed. Are you willing to assume the risk?
Running your own product means that you are responsible for everything from legal to customer satisfaction. You need your own lawyers, you need your own customer support system, you need to process returns, you need to do the legwork when a customer doesn't receive a product, etc, etc. Are you ready to build that infrastructure? What happens if your trusted manufacturer disappears, goes out of business, or gets acquired by someone else and doesn't feel like filling your orders anymore? Sure, you might have a contract, but are you willing / financially able to take a company to court to enforce it?
Basically, there are huge hurdles that you need to overcome and I would encourage you to spend a little more time doing research here and on the internet. Like canucksfan said, there are lots of headaches associated with running your own business and assuming the responsibility of being the vendor and the seller. Yeah, it's nice to get a higher payout per sale, but that payout comes at a cost which, on small scales, often exceeds the increased profits you make.
