Is there away to make Digital Products Accessible to different membership sites?

Greetings, 

I'm wondering if there is a way to make one digital product available to different membership sites and make the price based on the membership tier?  Or do I have a create a store for each membership site that contains the digital products within the membership site, and set the price from there.  If this is the case that means I need to upload the same digital product to each tier which creates a situation where I have to mange the same piece of content in multiple places.  I'm curious if anyone else has experience with this?

Thanks for any insight you might have. 

+1 to this! Wondering the same thing for awhile. 

Actually I was looking exactly the same.
In my case is a list of products; if you are not member you do one payment to download, if you are a member, you have it for free.