I'm considering FF forms for the development of a new User level "inventory" system.  I'm hoping that someone can advise on which tier I need to go with based on a high-level App specification (considering that I don't want to fork out unnecessary funds if I don't need to).
Basic functional requirement:

• WordPress website 
• User Registration
• "Global" Database of collectable "items" (including relevant attributes)
• User search Global item database:
  • User select a result from search result
  • A form is auto filled with core attributes from selected result
  • User can complete additional form fields
  • Submit Item along with form fields to user's personal inventory
• Require a page where User can view, edit and explore their personal Inventory

I thought Basic tier would suffice; then realized that the FF Views plugin which come with the Plus tier would be valuable in displaying a User's personal inventory; but then I saw that the Business tier has the User Registration component which is a requirement for my system...  Looking at Elite the Directory plugin could to be a possible solution for my requirements, but this subscription seems like overkill for my basic application website!
Any advice or guidance would be greatly appreciated.
Thanks
Rudi
p.s. Do note that I have no WordPress or website development experience - I'm new to all of this and on a steep learning curve :)