medicare w/ suppliers like edgepark vs. individual companies

My questions are thus:

I have medicare only.

Is there a provider that accepts the medicare amount as payment in full for ostomy supplies? 

Edgepark does not.

Edgepark says that medicare will cover 80%, and I will be responsible for the remaining 20% with NO DISCOUNT on pricing.

Are there other Edgepark equivalents that people use?

Or...

Is it better to order directly from a company that DOES accept medicare as payment in full?  Does anyone know what companies do?

So overwhelming.  I know it will get better, but right now I feel like I'm learning a foreign language in fast forward.

I am poor.  I  need as much "coverage" as I can get, and if that means going with slightly less desirable pouches for a while, so be it... I just need them from somewhere that isn't going to cost an arm and a leg, like edgepark.

Any advice and/or experience on this issue will be most welcome!

Thanks in advance... you guys have been awesome so far.  I thought I was spoiled over at my crohnie board, but you guys rock too!