I think their target was wrong. They should not try to get 'better quality' products such as knives, rather stuff that cant be made, are way more rare or just doesnt exists yet. Imagine selling shampoo and hair conditioner to a noble's family, so their hair would be clean, shiny and smelling better than flowers? You would profit so much off of that, and there would be less risk of them trying to re-sell this stuff (they would want to keep it to themselves), so the price upfront would be higher. Heck, you could probably buy a city if you were to supply this kind of thing to the higher nobles and king.
Or clothes even, doesnt even needs to be expensive ones, just pretty and decent quality clothing would sell for a lot. 100% cotton underwear? Geez, that would be so good.