There is no Looker Studio Pro subscription for around 3000$ a month. You can see the pricing on our marketing page. Whatever it is you are referring to, please share the link here for better understanding.
As far as the features go: every user that has a pro license assigned, will be able to use the features that come with a pro license, as for example the mobile app usage. There are no different tiers of pro licenses.
If you have more specific pricing questions, the best bet of course always is to contact your responsible Google Cloud Sales Specialist.