Threshold for quantity discounts has historically been five active licenses, but that was partly because it was always a manual process to set someone up for getting discounts.
Now that we have a decent shopping cart with code we sort of understand, we can automate that. I could see making quantity discounts start kicking in earlier, maybe even starting at just two.
I can’t make promises about when we can find time for that (it’ll take at least installing another module and a bunch of testing, and maybe even custom code since I don’t know how common our particular quantity discount usage would be…we’d want discounts to apply based on total number of active subscriptions, not based on quantity in one order), but it’s something I’d like to see. I don’t like maintaining the discounts roles manually.