amac is absolutely correct. If the items you want to sell are already listed on Amazon, and they most probably are, you are not allowed to relist them again, separately - you have to piggyback yourself onto the existing listing, and that means you have to compete on price. Unless you can win the Buy box, which is really, really hard to do, you will sell pretty much naff all.
As amac said, the key to making real money on Amazon is either to find a supplier with items not currently listed, or invent your own branded products (everything is available from China), making sure your products have an 'angle' that gives them a chance to be found by people with niche requirements.
The real key to success on Amazon is research, research and more research - keywords are vital. Go on Amazon and type in a brand name - for example, 'Ted Baker' - you will see Amazon's keyword suggestions underneath. This tells me people search for 'Ted Baker purse', 'Ted Baker makeup bag' and others. Do this and then see what results you get from these searches for specific product types, which have been made by previous visitors (that's why they come up as suggestions). but it doesn't have to just be about brands. If you just type in 'makeup' you can see that 'makeup organiser' is a popular search - over 1,400 products come up though! Some people search for 'makeup organiser black' - now you are down to 203 products. Hone it down to see if you can find any gaps you could fill, or at least where there isn't much competition for you to aim at.
If selling and making money on Amazon was as easy as getting hold of some designer goods and listing them, we'd all be millionaires by now. I hope you don't think that's a mean thing to say, I just don't want you to waste your time and money without thinking hard about the realities of it, first.
All the best
