allow certain clients to schedule certain events

Hello! I would like to allow some clients to schedule certain events.

Scenario: I have 2 service offerings --- "Tier 1" and "Tier 2".

Note: I haven't set up a membership flow for purchase of "Tier 1" and "Tier 2" at this point. Purchase of the Tiers is available through my shop page only for now.

Need:

• Clients who purchase "Tier 1" are only allowed to book services A, B, C
• Whereas, Clients who purchase "Tier 2" are allowed to book services A, B, C and services X, Y, Z

Questions:

1. Is this possible with the current flow I have described; eg Clients purchase Tier type through shop page and then schedule allowed service types (and how)?
2. Is this possible with a 'members area' flow (and how; eg. different member levels and experiences)
3. If you had to do this in the simplest way possible from scratch, how would you do this?
4. What is the best method if I wanted to expand from 2 Tiers to 4 Tiers, each with additional allowed services?

Thank you tremendously!