All buyers have 100% positive feedback. Sellers cannot leave negative feedback. (But you could run his name on Toolhaus for FB from before the policy was instituted.)
This is a common scam. Members are not supposed to make offers unless the seller has opted to recieve Best Offers. So you already know he is a bit of a scofflaw.
And you are dealing in a high fraud/high testosterone category.
You would save the 10% seller fee
Uh-huh.
He wants an off-eBay transaction. Even more of a scofflaw.
Silly twit doesn't know that Paypal's seller protections are very similar and almost as strong as eBay's. Criminals are often dumb.
Thank him for the offer and invite him to bid.
If he wins (chances are you will never hear from him again. This is not a bad thing.) be sure to ship with a service that used Signature Confirmation of Delivery. Belts and braces time.
Politely.-- Captain Malcolm Reynolds.