Adding my two cents here since I've been navigating Amazon for over a decade. In my experience, trying to do this manually by sending individual links is a huge time sink. I once gave a relative my login so they could pay for a gift, and it took weeks to untangle our credit cards and history... never again. You really need to be careful about the shipping address tho. Even if he uses a tool like Share-A-Cart to grab your items, Amazon usually defaults to the buyers primary address. Make sure he double checks that it's going to you. It's a common mistake that can cost a lot in return fees if you're not paying attention.

• avoid sharing logins
• confirm the delivery address I've tried many workarounds over the years, and a cart sharer is basically the only reliable way to handle 15 items at once.

I totally agree that lists can be a huge pain for larger orders. Tbh I had a similar issue when my sister wanted to help with my move last year. Amazon doesnt have a native button because of security concerns, but I eventually tried Share-A-Cart and it handled the technical side pretty well. It felt like a reliable option for me.