There is a big split between pro and home cook in japan. Professionals have their knives in sight of customers and the mindset is that any patina is dirty. Likely they clean and polish their knives at the end of every shift with daikon radish.
Home cooks probably are using german stainless steel santokus to be honest
Some professionals have their knives in front of customers, others think this is a disgusting practice. As to what is considered attractive, certainly large bevels will be polished at least daily, but beyond that, it really depends on what the chef likes and what he thinks his customers will like.
Home cooks are probably using Japanese-made Kai santoku, stainless, possibly teflon-coated. You can get them for $10-$15 (USD) at any hardware or home supplies shop. Those who like to cook also have a small deba, perhaps 160mm, and a small yanagiba or similar, perhaps 195mm; these are likely inexpensive carbon steel jobs, about $70 total for the pair, depending on where they were purchased. An upgrade of one or both knives at a local knife shop that will also do sharpening, polishing, straightening, and handle work for free or close to it is likely if mom is into cooking at all.
I'm more inclined to think that keeping knives (and swords! ) polished and impeccable looking seems to be more in line with tradition. And I guess a better way to put the cost factor is not that the main motivation is corners are being cut to be cheaper, but that how would this KU finished knife garner the same price point as the polished one? Perception of cleanliness or possibly "quality" plays into that. I haven't browsed and run into a KU usuba or true chisel ground KU yanagiba yet /img/vbsmilies/smilies/tongue.gif
Edit- panini I think I understand what you're saying better now. Those knives which are from a more farming/otherwise rustic region within their Japan, representing their origins?
Swords have nothing to do with it. You keep a sword polished because (a) it belonged to dad or grandpa or whoever and it lives behind the little family altar, and although it's a pain in the butt you do have to have it polished every few years; (b) if you don't, grandma will flip out when she sees it, and you'll never hear the end of that one, not to mention all the guilt; (c) if you don't, its value will go from modestly significant to nil quite quickly.
That all said....
KU knives are country knives, made in places like Hyogo and around Shikoku and so forth. They're traditionally made and sharpened and such by blacksmiths, and sold to ordinary people. Professional knives have very little to do with these traditions, and the main professional knives we know today (yanagiba/takobiki, usuba, etc.) are quite young, having been developed to their current norms only in the 19th century.
The practice of cutting things in front of one's customers is very young indeed: it originates with cheap street stalls in large cities (Tokyo, Osaka, etc.), after the Meiji Restoration gets going and you have this high-pressure rapid modernization of the urban male workforce. That is also, not coincidentally, the origin of edomaezushi, the style of sushi everyone thinks of in general as "sushi." Outside of this particular rather narrow tradition, cooks and servants and the like do not
ever handle sharp blades around their masters, especially at close quarters. Once upon a time I suppose there was some practicality to that, but mostly it's just sort of rude and not done.
The result is that it is only very recently indeed that any professional might ever consider a KU knife. What's the point? They don't come in the right shapes, they're ugly and sometimes smell funny, and they're really not so cheap as all that.
Of course, if you do want a true chisel-ground nakiri to chop your veggies at home, then a KU knife like your grandmother had is a great option. After all, it's not going to cost more than, what, $25? And the guy you bought it from will happily set it on a wheel and put a scary edge on it every few months when you need it.
That all said...
You have to wonder: who's the intended audience for a KU knife priced north of $100 USD? Not a Japanese pro: either he needs his knives beautiful (edomaezushi etc.) or he needs pretty much exactly what he was taught to use (other traditions). Not mom: why should she spend more than $25 -- is she going to show off to her friends? I don't see a lot of conspicuous consumption going that way. So... let's see, maybe male hobbyists with more money than sense, who care more about the looks of things than their utility? And who quite possibly aren't in Japan and so that $100 price tag suddenly isn't daunting, because there's nothing lower on the market?
In short: don't overthink it, OK?