But this "unlimited" is only unlimited if you have at least 5 users. Otherwise its 1 TB. Can you confirm?
Yes, kind of. First, I've seen reports from users (including, I believe, here) with single-user accounts saying they're storing over 1 TB without issue. Second, there are a bunch of probably-bogus accounts on eBay that promise unlimited storage. But third, accounts bought through an authorized reseller are unlimited even if you only have one user on the account. One vendor that's working toward that status is gsuites.org, though it looks like they're still in pre-sale mode until they can hit 100 users.