Paid google apps + free for subdomain

Question

Google

The question has already been raised , but decided to play it safe and ask again.
I have a paid google apps for a domain, I bought mail for the 21st user for 40 euros for each per year.
Now there is a question to transfer 30 more users with non-priority mailboxes to gmail. But 51x40 = 2040 euros per year is expensive.
There is an idea to make subdomains on the site, for example, sklad.domen.com, etc. and sign up for free accounts. But I'm afraid of losing a paid subscription. Has anyone done this? Don't get hit on the head? Polisi somehow do not want to read, maybe there are seasoned?
Thank you.

Answer 1

we do it this way, only not a subdomain, but just different domains (they differ in regional prefixes), there are different redirects (that is, you can definitely determine that the company is the same), I administer from one IP address - for more than a year the flight has been normal, there are no problems .
And all google apps are free.
For the sake of economy, they did the main domain for another 50 users, but it was no longer enough.

Answer 2

Do it calmly.
For angle, your 3rd level domain will be as a separate domain. We did this in one organization, there were 3 domains of the 3rd level, and one main one in a paid account. Further, one of the 3rd level domains was also transferred to a paid basis, because there were more users.
In a word - no problem.