Hi inavarrorubio,
We'll keep your request in mind and will post here once we encounter any supplier that offers discount programs of such type. :)
A common discount I have seen are of the tier types, the more you order the cheaper the prices. You can also see some special price offers at a limited time, posted by the suppliers here at the forum, like Link hidden: Login to view
I also would like to mention that some suppliers will be willing to negotiate better prices with resellers that they have a good relationship with. :)
Have a great day! :)