How many people can use an individual plan?

Hi Hannah, I was just going through this thread and wanted to raise a similar query to which Viraj has raised.
I am planning to purchase the Dropbox Essentials plan in which 3TB storage is provided. I have a project which requires ample storage capacity to store all its database and I feel 3TB will suffice for this requirement. My project is distributed between 8 regions where all the project activities are implemented. Now, as the owner of the parent account, I have designed my dashboard into 8 separate folders under which each folder has 6-7 sub-folders based on the various components of the project.
Eg: Region 1- New York (Mother folder)
a. Municipal activities (sub-folder 1)
a.1. Pictures
a.2. Reports
a.3 Videos
b. Sustainable Development Goals (Sub-Folder 2)
b.1. Pictures
b.2. Reports
b.3 Videos
c. Livelihood activities (Sub-folder 3)
c.1. Pictures
c.2. Reports
c.3 Videos
d. Case studies & Success stories (sub-folder 4)
d.1. Pictures
d.2. Reports
d.3 Videos

Region 2- Texas (Mother folder)
a. Municipal activities (sub-folder 1)
a.1. Pictures
a.2. Reports
a.3 Videos
b. Sustainable Development Goals (Sub-Folder 2)
b.1. Pictures
b.2. Reports
b.3 Videos
c. Livelihood activities (Sub-folder 3)
c.1. Pictures
c.2. Reports
c.3 Videos
d. Case studies & Success stories (sub-folder 4)
d.1. Pictures
d.2. Reports
d.3 Videos

My aim is to give access to one user per region i.e. 8 members wherein they can start uploading all their project related content systematically into the specific folders and sub-folders I created for them on my parent account. 
Based on my requirements as stated above, I was informed by Dropbox sales team that under the essentials plan, I have the following options to choose from- 
i) Option A- give the other users access (view & edit) to the folders wherein they can start uploading their data. However, this requires them to have an individual dropbox account with enough storage capacity to upload the required content. I cannot choose this option as this will require the other 8 users to register for dropbox and purchase their own plan. Some might have the free account with 2GB storage but that won't meet the requirement as the data they need to upload will exceed 2 GB. And some might not be willing to register an account with Dropbox.

ii) Option B- to share "file request" by sending individual links to the users so that they can upload the content. Through this option, the user does not need to have a dropbox account. He/she receives a common single link where they can upload the data.
This option seems inconvenient for my situation as the common single link does not give them access to the various folders and the sub-folders I have created. If I go with this option, under New York region, I will have to send the user 16 separate links to ensure that they only upload the data as per the required sub-folders I created. This can be quite a hassle, time consuming and confusing for the end users. It could result in them uploading data on the wrong link shared.
iii) the last option provided was to choose the business plan where I could add other users on my account under a team account. But the tariff is quite high which does not suit my budget.

What in your expert opinion can I do here??? I just want to let other users upload content on my parent account without having them worry about having enough storage. Only the storage from my account should be used.
If I have to go for option 2 where multiple links have to be sent to the users, do you have any practical/convenient suggestion for me to work this out???

Thanks