Rick,
Of course I noted the sarcasm in you post, but... As a retailer we're expecting you to take a markup of some sort. The difference between a retailer that has the respect of it's regulars and one that becomes nicknamed "worst marine" is, now that you know where to get it at $5 a tube, will you use that supplier and pass the savings on to your customer... or will you use that supplier and continue to charge 12.95 per tube?