Cost of Different Assistants API Functions

Hi guys! Really big fan of the Assistants API - was just wondering a few things that will impact a website implementation I want to carry out.

When users open my website, they’ll have to pick a number from 1 - 100. Once they do, they can speak with my Assistant, which will use file search to respond to the user, but will strictly retrieve data from one of the files 1 - 100 (according to which one they picked) which I’ll upload to a vector store.

I’ll need to handle multiple users at once on my website (so will need new Assistant per user session) and I’ll need to keep vector storage costs as low as possible (so will need to upload & expire specific file per user session).

I was wondering, is there any cost to creating a new assistant or uploading files to a vector store, since I will be needing to do these a lot? Are there any flaws you see in the design I’ve covered?

Thank you guys!