Day At The Range has a review of a custom-built 6" SVI Infinity.
A truly bespoke pistol is something a lot of shooters will never experience, and one that is done right is an even rarer beastie.
One common belief is that the money is spent on pretty; cosmetic fripperies that have nothing to do with the function of the heater in question. I suppose it's possible to sink bucks in various styling curlicues and gingerbread, but that's missing the point. Sure, I'll look at things like how well the beavertail is fitted up or how nicely the ass-end of the extractor is blended with the slide, but I only do that as a gauge of the craftsman's attention to detail: If he didn't care enough to handle these visible areas properly, why should I think he spent the time to do a proper relief cut on the sear or make sure that the feed ramp geometry was precisely correct?
Understand this: By comparison to a true custom 1911, even the nicest Kimber is a mass-produced gat that is only distinguished from its more plebeian brethren by its price tag. Sit down with a Brownells catalog and start tallying up the tariff on a high-end gun: Forged frame and slide, Kart barrel, Cylinder & Slide lockwork... You're over a grand before you've even gotten into the nitty-gritty of triggers and sights and slide stops. Pick your choice of everything, sized and shaped to your hand and style of shooting. Make sure it's made of top-shelf materials; no cheap slag on your Excalibur. Select a truly skilled craftsman to assemble it (and that's the hardest part, right there; there are dozens of gun monkeys for every guy who really knows how to make a 1911 sing,) and pay him appropriately... Now you know why these things cost money.
But when they're done right, oh my. When you have sweated and agonized over each part, building exactly the gun you want, fitted to your hand like a glove, well...