The profit margins are slim to non existant when it comes to dropshipping. It's very hard to find a decent dropshipper although there are a few out there..The trouble with dropshipping is that there are so many people trying to do it that the market is flooded with their products..
Plus on top of that most of the dropshippers are not really that. They are just middlemen posing as wholesalers. This means that they are actually buying their product (which they want you to sell) from an actual wholesaler or distributer. So they are paying a mark-up to that company. Then they in turn to make a profit are marking it up to sell to you. So right off the bat, when you buy from these types of middlemen you are already paying 2 markups on the item you are buying..
In addition most of these guys want you to pay a 'fee' to join their program and most of the time they require you to do this before you can even see the prices of the products they have listed....Most of the things that they sell can actually be purchased cheaper by driving down to your local dept store...
Also they have a bad habit of not actually keeping in stock the items that they do dropship..This can absolutely kill your feedback and business. Because you can sell an item and you customer is expecting at least somewhat of a speedy delivery. Then you will get a notice from your dropshipper saying the item is 'out of stock' and on 'back order'..And the bad part of it all is that your customer is NOT going to blame the dropshipper, they are going to be looking at you for an answer...
Probably the best advice I can give you is to decide what type or types of products that you intend to sell. Once you decide that, try a site like liquidation.com, or surplus.net, etc. where you can actually buy items in bulk and make a profit on..Buying in 'lots' and in bulk is really the only what you are going to be able to get ahead and make some real money..
Too, if you are selling on ebay, or plan to, keep in mind that most all of the products that you see on there are normally sold at 'below wholesale' prices...This is why it is so important to find items that you can buy in bulk (quanity). Normally when buying this way the more you buy the cheaper they are going to be..When buying items through liquidation and close-out,and surplus sites, you can actually get items for pennies on the dollar...This is how you need to compete with the other sellers on ebay or any other auction sites....
And remember, when you are buying in bulk, and selling in bulk (that is, lots of items) you don't really have to have a huge market. Since you are selling numerous items,(that you purchased cheaply in bulk) it only takes a small profit on each item to produce a good days or good week total profit..
This is how most powersellers operate..They can undercut their competition by selling their items at a very low cost, probably only making a couple of dollars on each item,,,,however since they are listing and selling hundreds of items each day, their profits are actually very high...
This is why national chains like 'walmart' can sell items so much cheaper than other stores. They are selling thousands of products every day, so they only have to make a few cents on every item....