You ask good questions. Here are my two cents' worth.
A khukuri's design seems to give you a chopping advantage over a straight knife of similar length. This (if my perception is accurate) lets you carry more chopping power in a smaller space with a khukuri than with, say, a golok or bolo. (I didn't say "machete", since most machetes are thin of blade, and seem better suited to very light brush than a golok or bolo.) e
As mentioned by someone else before, khukuris, with their longer edges than axes, seem to do better at cutting what you're aiming at and not missing or glancing off. This also makes them great at cutting lots of small, thin branches or twigs off of a larger branch or tree trunk: you can chop multiple twigs in one stroke, which might take 5 or 6 blows with a hatchet. As with a hatchet or axe, YOU MUST BE CAUTIOUS ABOUT WHAT YOU'LL HIT IF YOUR BLADE GOES THROUGH THE TARGET--good idea to stand on one side of the log you're limbing, for example, while cutting off the branches on the other side.
A khukuri, unlike an axe or hatchet, also doubles fairly well as a knife--it does have a point, which, though sometimes not hardened as well as the edge in the prime cutting zone just distal to the curve, will still let you skin animals, cut things, etc. in a pinch. For what it's worth, traditional khukuris also come with a small by-knife, or karda, and sharpening steel, or chakma, so you actually are getting a little extra for your money. Karda and chakma quality and hardening are hit-and-miss, but if you want, I'm sure you can melt the adhesive holding the steel into the karda and chakma handles (this adhesive is called "laha"), heat the steel to non-magnetic, quench it in water or whatever, re-melt the laha (or use epoxy), and you'll likely have them functional, if you don't find them so initially.
Khukuris---especially the quality handmade ones--have a lot more character than production knives you'll get. I mean, there's just something to a quality wilderness knife that started life as a truck spring, was hand-forged over a charcoal fire near Kathmandu, and handled with water-buffalo horn. Beats Kraton for character any day. Also, I imagine that smiths in Nepal's "untouchable" caste may need your cash a little more than, say, Cold Steel LLC does. (No offense, Lynn!)
In the case of Himalayan Imports, the warranty and customer service are almost unbeatable. H.I. encourages buyers to chop their new knives into logs, etc., and lean on them and pry them to make sure they won't break. A very few do--it is theorized that sometimes the khukuri-smiths' old-fashioned heat-treatment method (consisting of pouring hot water from a teapot onto the cherry-red edge, gauging the temperature change by eyeing the color) misses, leaving the tang or ricasso area harder and more brittle than intended. If the original purchaser breaks an H.I. khukuri (other than by intentional abuse), H.I. (as I understand it) will replace it, free. Two exceptions: they have a model called the "kobra", sort of a thin, fast, martial-arts knife, that may be exempt from the usual warranty, just as a necessary function of its exceptional thinness. They have another model, the chiruwa ang khola ("chiruwa" means "split", referring to the handle construction, which uses scales on either side of the tang, instead of a rat-tail tang like most khukuris have) which is so heavy-duty that H.I. offers to send you TWO chiruwa ang kholas if you break or bend one. What this means for me is that I can actually afford to test the heck out of each H.I. khukuri I get, BEFORE I take it way out into the middle of nowhere (or give one to my wife or one of my kids to do the same) and rely on it. I don't believe Ontario or Ka-bar will look as kindly on a knife returned in multiple pieces because you chose to chop it into a hardwood log and lean hard on it.
Finally, as to price, the list prices you see are usually well above what one can get by lurking on the H.I. subforum on BladeForums and watching for the almost-daily "deals of the day" posted by the proprietress, Yangdu Martino (Reno, NV-based widow of H.I. founder, the late Bill Martino; I think she's the daughter or other relative of the master smith in Nepal--who, incidentally, before the recent end of the Nepali monarchy, was supposedly the khukuri-maker to the king of Nepal). One very often sees H.I. khukuris offered for sale for maybe $65 and up. You need to have a good idea of what you want, and of what kind of blemishes you're willing to live with, and then to be VERY FAST to e-mail Yangdu with an e-mail saying you'll take it, with details of your address and payment method. The best deals tend to disappear about 5 minutes after they're posted. But a little bit of rust that you can take off in 5 minutes can drop the price by 50%, sometimes--as can a small handle-crack that you can fill with epoxy.
As to the particular model for you to try, I'd recommend the British Army Service ("BAS") model. It's 15 inches overall, which means a 10-inch blade. It'll chop respectably, but isn't absolutely huge, and I tend to find myself picking up a BAS when I'm going on an outing, leaving the more-monstrous knives behind. The ang kholas are usually thicker in the blade, which makes them a little more unwieldy for things other than heavy wood chopping. If you keep an eye out, you can probably get a slightly-blemished but fully-functional BAS for in the neighborhood of $75. (The H.I. prices include shipping within the continental U.S., by the way.) Actually, even the narrower-bladed knives such as the sirupati and chitlangi are often substantial enough to do some woodchopping--wouldn't want to build a log cabin with one, but if you just want to cut a few inch-thick branches and drop a couple of ten-inch trees, you could do that with any chitlangi or sirupati I've seen. Might take you a few more blows, but, hey, they'd work. There IS a lot of blade-to-blade variability in these handforged knives. One of my favorites is a chiruwa ang khola "villager" (H.I.'s designation for a less-polished knife, typically sold at a discount, though the unpolished finish may mean that the heat treatment stays better intact); it's got a blade that's only maybe 3/8 of an inch thick--unusually thin for a chiruwa ang khola, whose blades are often a full 1/2 inch thick at the spine); great heat treatment, with a nice, razor-sharp convex edge that I've developed over years. It sails through wood with surprising and dangerous ease.
Happy shopping. And happy chopping!