Hello @anonymous_user_843ce987,
I’m a UE4 Blueprints Developer (please view Forum Profile). My game is my portfolio/resume. Although I prefer Royalty Projects and Skill Trade, I have to admit your Paid offer has my attention 
somewhere from $50 - $100 per hour was our expectation.
Upfront, I would utilize Asset packs from the Marketplace like those listed above to have a prototype up and running as fast as possible. A large portion of my Blueprints experience is reverse engineering, modifying, integrating, and engineering new Blueprints as necessary to achieve a desired goals.
Allow me to take a gander at your Notion document detailing the various rooms, puzzles, solutions, etc. to ascertain suitable assets for achieving the prototype as fast as possible. Afterwards, I’ll present you with a Detailed Development Proposal a.k.a List of Assets matched to desired features.
If a feature requires extensive engineering or presents a significant technical challenge, ill highlight the facts, and present alternative solutions if necessary in the list as well. In fact, I’ve already picked out some Asset Packs based on your description:
first level (3-5 rooms with puzzles) and build out the fundamental gameplay mechanics (inventory system, netplay, triggers&events).
You review the Development Proposal and make a decision to move forward. If you elect to move forward, I would request setting a specific budget that includes asset acquisition expense and a starting payment equivalent to 6 hours of integration @ the rate of $100 Payable via Paypal/Cashapp.
I prefer to setup Perforce Source Control Server for proper project collaboration and version control. The Free License has 5 User seats. Collaboration will be required for Technical Communication, Resource Sharing, Development Testing, and Play Testing. Lots of Play Testing.
Lets get the ball rolling on Discord. Thanks for Reading. I appreciate your consideration.