A lot of internet shops, not all but more than a few dont stock any product. You give them your credit card and they have your money for probably 30 days before they have to pay the distributor who they got to drop ship the knife to you. They have a phone, in a room with one person answering it, or they dont list a phone contact and you just email which they check when they can, business may have one employee.
The brick and mortar guy usually has the knife in stock, $10k worth of knives means your paying interest on it, or you should at least be looking at what your money could make in bonds or whatever (not stocks for now), liabilty and product insurance, water bills, electric bills, city and county taxes, building rent, unless you want to work 6 days a week with no time off they will need a 4 or 5 employees if they plan on staying open for any amount of time, weekends, 10 hours days, back ups for sick days, that sort of stuff...
Really not hard to see where the extra expense comes from.