Most brand new intenet business owners that get into dropshipping products come across the same challenges, and the most obvious one is pricing.  Most new internet business owners are not established in business (let alone the internet) and they have no reputation to show the supplier they are for real.  So they (the new internet business owner) has to spend time proving to the supplier they do know what they are doing and they are "in it" for real and long term.

The best way to prove to your suppliers you are for real is to get search engine rankings and traffic from those rankings.  If you can show them you are getting 500 unique visitors a day (naturally) BUT no sales, its easier for you to negotiate a better price on products because YOU WILL MAKE THEM MONEY if they give you a price that you can compete with.

So be patient in getting started, you may have to have a few months of establishing yourself on the search engines and getting the traffic so you have the "proof" to take to your suppliers to get better deals or products.  They want to make money (that is thier bottom line) so if you can show them even a glimpse of how you will make them money they will be much easier to deal with!

Just as a reminder when you establish a relationship with a supplier it does not mean you have to stay with that one supplier forever.  You have choices and can select a supplier that will give you the bottom line best deals and service.  There is nothing personal in business, you want to make money and that should always be your bottom line.