Where do you get your knives? Online? If yes, where, amazon, cutleryandmore? In brick and mortar stores, which ones, Sur La Table, Williams Sonoma, Macy's? Do you ever buy from reps that come to your restaurant?
I tend to go to the stores that have a large selection that I can put my hands on regardless of price. Without buying but knowing what I want to purchase, I then search online for that particular model at the cheapest price available. Buying a knife that you haven't handled and seen if it fits the particulars of your hand doesn't seem like a good decision to me. Finding exactly what you want then shopping for the best price does.
I have never bought a knife from a rep, but if I found the right one, I don't see why I wouldn't. But since knives tend to be a bit expensive, I usually have to plan to buy them and don't make impulse purchases. Reps usually (in my experience) don't give too much notice before they show up not giving me a chance to plan for a purchase.
Knives are very personal. You have to hold them and feel how they work in your hand before you purchase them. Thus, I usually purchase blades that I have actually had the chance to hold and demo.