The problem - such as it is - is the mixed message carrying a production knife sends to the buying public. Educating the public on the value of custom versus production knives is one of the greater hurdles to bringing more buyers / collectors into the custom fold. If you've got an ABS Master Smith at a show with a trio of $600 to $800 carbon steel hunting knives on his table and a customer walks up and askes why they cost so much, no doubt the maker could explain the benefits of hand forging to shape, careful heat treating, hand grinding and finishing, meticulous attention to blade geometry, selecting premium natural handle materials, how he stands behind his work for life and how, with proper care, one of his knives will last for generations.
"Wow, pretty impressive," thinks the customer. Then he glances over to the maker's hand-tooled leather belt with its big bright silver coboy buckle and asks "What's that you're carrying on your hip?"
"Oh that?" responds the MS - "That's my $50 Buck hunting knife! It's my favourite! Carried it for years and it's never let me down. My dear Pappy, God rest his soul, carried the same model his whole life!"
You all tell me - what's that customer's next purchase likely to be? Substitue any custom versus production example you want and the resut is the same. A maker selling high end custom chef / kithhen knives that uses a $20 WalMart set i a plastic block in his own kitchen? The optics kind of suck.
I'm not trying to disparage any custom maker who chooses to carry a production knife for whatever reason. Certainly, makers in this thread that I know and admire - like Senor Hanson - make knives of unsurpassed quality that will be coveted by collectors regardless of what's in their own pocket. I just ask that you consider the very positive endorsement of your own product in particular - and custom knives in general - that can be presented by carrying your own work.
And don't think that carrying and using the knife means you can't sell it. A lot of guys find a maker's personal knife a really appealing buy. Of all the knives in my collection (which are pretty damned nice, if I do say so myself) the one with the longest line of fellow collectors wanting to make it their own is a damscus hunter that I liberated from the hip of Burt Foster a couple years ago. It had been used by him for nearly a year at that point, and has been used regularly by me ever since.
Finally, with respect to those who claim differently, if you are a full time maker and you ar telling me that, amortized over your entire knifemaking career, you can afford neither the time nor the materials to make and carry one of your own knives, well... all I can say is you really need to take another close and careful look at the math.
Roger