As a pro web developer and online marketer, I can say with confidence (and analytics) that the value of a simple link to the store from the header is overrated. Online buyers are frankly much more savvy than that and won't simply buy products because there happens to be a link in the header.
Jason/BSO specializes in strings and as such TB'ers are buying his expertise, bundling, and pricing, things difficult if not impossible to find elsewhere on GC, Amazon, etc. Paul could put a direct link to GC on each every page and BSO would still continue to sell strings to TB'ers as long as he continues to offer his advice in the forums.
Selling fungible products at a TB store makes little sense in my opinion since the TB store will never be able to compete on pricing, service, shipping, etc with Amazon, eBay, GC, and even BSO. Rather, the TB store should focus on the unique and licensed (which means higher profit margin) items that make TB what it is. Many of those potential products have actually been mentioned in this thread.
Moreover, if Jason is claiming that his posts are done for informational purposes to help the community make smart decisions, his decision to stop posting proves his lack of altruism to the community. Make no mistake that his helpful posts are advertising else he wouldn't be threatening to stop posting.
This stand-off between Paul and Jason will be a lose-lose situation IMO. In a year's time, Paul will have discovered that the store is underperforming by not focusing 100% on TB swag and Jason's business will have taken a huge hit in sales due to his emotional decision to stop 'infotising'.
Memories are short and the majority of BSO's customers from TB will have moved on to other sources.