A Budget Light: "I know it when I see it." - Justice Stewart, 1964
Thought I might try to shed some light (pun intended) on the definition problem. Someone mentioned "wine" as an example early in this thread, and I think that is an excellent analogy. I also think "restaurants" are another good example.
Anyone (if they are willing the pay the price) can go out to the "very best restaurant in town" and enjoy an excellent meal. Unless you are extremely unlucky, or have been poorly informed, so long as you are willing to spend the money, then you can fully expect to enjoy a truly exceptional meal with great service and ambiance. (I enjoy meals at expensive, sometimes very expensive, restaurants. But, I rarely spend my own money. Usually, someone else is buying!)
If you are just visiting in a town and desire "a truly exceptional meal," then you probably end up having to spend the necessary money in order to guarantee quality. But, if you are a local, and have had the time to spend "researching" new and sometimes old but "unknown" restaurants, then you can usually find a way to enjoy the same, or similar (or perhaps even better) meal, at a greatly reduced price.
By the way, this kind of "research" is more of an art, than a science. (I think it should be considered a "fun hobby" where you accept the bad with the good, in the spirit of entertainment. It is sort of like going fishing. You never know what you might catch. So, in that sense, I think of "Budget Lighting" as a hobby or sport that involves the process of successfully seeking out "Budget Lights.")
Anyway, first of all, you need to know what "a truly exceptional meal" is supposed to taste like. If you don't know the truly "good stuff" then it is hard to know it (even when you see it) at a budget price.
Take sushi as an example. The highest quality raw fish can be extremely expensive. Despite the recession, you can still easily spend $500.00 per person in Ginza, if you choose to go to such a place. But, for that kind of money you have a right to be very very unhappy if there is even the slightest thing disappointing about your dining experience.
On the other hand, there are many excellent "budget" sushi shops in Japan. Look for very busy large chain restaurants that serve only sushi. They are able to purchase their raw fish in huge (discount) quantities because they operate a large chain. And, if they are extremely busy, the raw fish stays really fresh because they sell it so fast, it doesn't have a chance to get old. You can get a great sushi meal for way less than a 10th of the Ginza shop (probably more like a 50th!)
But, stay away from your local neighborhood sushi shop and other "middle-of-the-road" sushi shops. They often have too few customers, and are often in financial trouble, so they must preserve the expensive raw fish that they have "invested" in, as best they can... and hope to eventually sell it before it actually spoils. (The only exception is, if you are truly "friends" with the sushi chef, he will tell you himself to avoid stuff that is getting a bit too old.)
Finally, what is the best value ("budget") sushi shop in Tokyo? Well, others are entitled to their opinion, but in my mind, I think of a couple of shops actually located inside the "restricted area" of the big fish market.
Things have changed some over the years, but these shops were intended to serve food and drink to the fishermen and others who have been up all night working at the fish market. Used to be, regular Japanese could not easily get in, but they would allow foreigners (tourists) to sneak into the "restricted area." Best sushi in town. Bar none. (But, the only hitch is you have to get there by 7:00am and get in line early, or else you may wait for an hour or more. Also, they sell out of rice entirely by about 10:00am and are closed again until the next morning.)
Anyway, I hope I have successfully expressed my point. I believe "The Art of Budget Lighting" is a kind of hobby or sport where you perform enough research and acquire enough experience and/or knowledge on the subject, until you can become a proper judge of a lower priced light's true worth. Otherwise, you are probably better off spending top dollar for a brand name that guarantees good quality based on their name.
I recently decided to look into AAA keychain lights, with an emphasis on those models that might possibly be practical for 10440 as well as primary AAAs. I intend to test them all with a 10440 to see which one might be most practical for my own use. And, then gift the "rejects" with a good primary battery (not a 10440). At the same time, I am also looking for a low cost, yet reliable enough light to purchase in "quantity" (10-20 pcs.) so that I will have some on hand to give away as gifts.
I selected three models in the $10-15.00 range, with High Only. Three models in the $12-18.00, with High/Low. And, five models in the $16-35.00 range, with High/Med/Low. There are many more AAA keychain lights out there (both cheaper and more expensive), but I figure that these will provide me with an adequate sample for my initial research. (A couple of the more expensive lights are name brand, so I would not consider them "budget lights." The question is how well will some of the cheaper models compare with those name brand models in both quality and performance.)
Obviously, a flashlight is a tool. And, in order to be useful (especially as an "emergency" tool) it must perform with a certain degree of reliability. If you cannot pretty much count on it to come on when you need it, it is not "budget." It is simply junk. (Just as sushi that might make you ill is not a meal, at any price. Unless, of course, you are truly starving to death...)
Sorry this got a bit long, but that's my "two cents worth."