If we only want to offer product as payment and the athlete’s social media buy states $3,000, then do they want us to provide them with $3,000 worth of product?

Not necessarily. Athletes, like brands, will have their reservation points and will always be on the lookout for the best deals, but that doesn't mean that somebody with a $3,000 buy in won't promote your product in exchange for a free one of their own. You can always test the water by sending an athlete an invite and hope they dive in!