Actually, it's clear the author doesn't understand how to list an Ebay auction to accomplish what they're trying to do. Here's how you could have done this EASILY:

1) Allow local pickup as an option on your listing (Does not cost anything!) 2) Put a Buy It Now Price and open it up to Allow Offers to be made.

I'm not sure why a buyer has an incentive to go off platform since after all there is no fee for a buyer to pay through Ebay. The seller pays all the fees so for a buyer to ask to go off platform usually is a red flag for me (scam, wire transfer, etc.).