Group Membership Tiers

Yes, the auto action that you provided works great.
You are correct, I am wanting to increase that based off the owner of the group and their subscription status?
For examples: Users start with a base allowance of 100, then could increase limit in increments of 250. Each increment will cost an additional monthly amount.
I was thinking of creating 4 tiers and using 4 corresponding usergroups to achieve this? I welcome your directions.

Ok, best way to do that then is to have an field in CB > Field Management for storing their limit. Ideally this should be a Number field type. You can then increase or decrease this as needed from your plans using CBSubs Fields. Once you've that working adjust your auto action condition to the following.

FROM
Value: 500
TO
Value: [FIELD_NAME_HERE]

Replace FIELD_NAME_HERE with the name of your field. The limit should now be entirely based off that profile field from the group owner. You may also have to adjust the following.

FROM
User: Automatic
TO
User: Specific
User IDs: [var2_user_id]

The only complication would probably be the email one. For that you'd have to use format functions and apply math. The below should work.

FROM
Value: 499
TO
Value: [cb:parse function="math"][FIELD_NAME_HERE] - 1[/cb:parse]
Format Functions Selected

Now you can adjust that field however you like to whatever you like and that will be their group user limits. If you want subscriptions to increase a static base value you could also use the below to hardcode that in if you wanted.

FROM
Value: 500
TO
Value: [cb:parse function="math"]100 + [FIELD_NAME_HERE][/cb:parse]
Format Functions Selected