From what I've heard I think you're very unlikely to get a discount via a group buy.
However, what I'd suggest doing is getting in contact with a reseller and working our the dimensions of a deal - we need something already worked out to commit to, an someone needs to own that. i.e. come back to us and say "If 3 people buy a full system the price will go down from x to y, and if 5 people buy a slip on system the price comes down from a to b". Otherwise no-one is able to commit to something that doesn't exist...
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