What is your distributor selling? Distributors by their name, provide services related to making available products and services that you need to run your practice and to provide exemplary care to your clients. They are logistics specialists who help ensure that you have what you need when you need it.
You might need the product, but getting it at the right time and at the right price is about the service. Many distributors provide same day or next day service, depending upon your location. Price is important. But, price alone is not the most important component of selecting a distributor.
The service of a distributor partner is very important. Knowing that you can reliably get what you need when you need it is a big issue. Price is important, but as long as you are marking product up appropriately and passing those costs (and receiving your necessary margin) on to your customers, getting the product at the right time, and not having to stock too much inventory makes a bigger impact upon the success of your practice.
Select your supplier partners based upon those that will help you optimize your inventory, both from a service and timing aspect to the cost as well. It may be more valuable to your practice to pay a little more for product, if you don't have to stock as much inventory knowing you can reliably receive it when you need it.