Product with variant and free download

-- url of the page with the problem -- : www.sources-vivre-relie.org
-- HikaShop version -- : 2.2.2
-- Joomla version -- : 3.1.5
-- PHP version -- : 5.3.16

Hello,

I have just installed hikashop. CBSubs and community builder are already running on my joomla. And I have a group of users called
"suscribers"(/Abonnés). The website is about a magazine.
With CBSubs once users have registered I would like them to be able to download for free the same items which are available in Hikashop but which are payfull for non suscribers (creating only one single item...)

I would like to be able to create a single item (magazine n°X) and then different prices regarding the caracteristics (or paper or electronic) and in a specific caracteritic (the electronic one) the price would be or X€ for non suscribers or 0€ for suscribers to cbsubs.

I have created one item - a magazine (n°X)
I have created 1 caracteristic - called "format" in which the value are or paper or electronic with different price each
and then I am lost...

Is this possible? and how to do that... or not what is the closest option?

PS: I don't manage to create a price "0€" with access level restricted to suscribers from CBSubs, if the price is 0 then or it disapears if there is a second price option or I don't have access to level access if 0€ is the only price ...

Thanks for your help,
Best regards