Quite a lot, at least in my experience ...
One questions I'm asked quite frequently is, "What's the best saddle?" And my answer always is, "The one that suits you and your horse the best." This answer often elicits a blank stare from the questioner, since most people expect me to offer up a particular make of saddle ... and seem to want me to offer up one that will set them back about 4 or 5 mortgage payments.
Sorry, folks, but I'm not a Name Queen.
I run into tons of people who practically pee their pants when they hear "Devoucoux", "Hennig", "Hermes", "Schleese" or "Antares", and I have to confess: I just don't get it. It reminds me of the early 1980s, when everyone (male and female) was squealing over Jordache or Gloria Vanderbuilt or Calvin Klein jeans, and I was noodling along quite happily in my Levis and Wranglers. They fit me better than anything with a designer label, wore like iron, and were less than half the price of the designer jeans. "But they don't have a name," my friends would moan in despair. My broke friends. My broke friends who were always complaining about their uncomfortable designer jeans ...
Saddles are much the same. Sure, you can pay $6000+ for a custom Hennig, or $4500+ for a custom Schleese (or Stackhouse, or County ...), BUT that doesn't guarantee that the saddle will suit you (or your horse) any better than an off-the-rack or bench-made saddle might. You and your horse might be perfectly fitted with a Black Country, and Albion, a Frank Baines, or (gods forbid) a Duett or (I'm uttering blasphemy here) a Thorowgood or Wintec ...
Why? Because most horse and rider combinations do. not. need. a. custom. saddle. Many can be fit beautifully by an off-the-rack model and a little help from a fitter, and the rest are just dandy in a bench-made saddle. Given the gazillion different saddle companies out there with a bazillion different models and a googolplex of fitting options, you can find a stock or bench-made model that will fit - there's no real need to go custom.
But some folks are just incurable Name Queens, and in that sense, they need to be riding in the trendiest, most expensive, sought-after saddle out there.
One of my customers recently spent $3800 on a wide tree used Devoucoux dressage saddle to use for trail riding on her very round little Morab. When I gave her the bad news (as gently as I could) that the saddle didn't come close to fitting and there was no way it could be made to fit, her response was, "I got a good deal on it though, right?"
The saddle was in lovely shape, and since they sell for well over $4000 new, at least I didn't have to tell her I hoped she'd gotten a kiss and dinner in the bargain. "Well, yes, but since it doesn't fit ..."
"But it's a Devoucoux," she said. "And I got a good deal on it."
For her, that was all that mattered.
I see this far more often than my saddle fitting soul would like. People buy the name, and whether it fits the horse - or them - isn't really considered in the equation. They have the cachet of saying they ride in a Devoucoux / Hennig / Schleese / Antares / CWD / Tad Coffin, and that's all that matters. It may be wearing holes in their horse's back and they may have their underware fused to their naughty bits at the end of a ride, but by gods, they're riding in a ____________ (fill in the blank). The world envies them, so having to wait 20 minutes after a ride before they can walk without screaming is of no consequence. And if the horse is going belly-down in the dirt when he sees the saddle, well ... just put another pad under it. Yes, they already use 4 pads with this saddle, but once Das Pferd gets to second level and develops a real topline, the saddle will fit beautifully.
Now, keep in mind that all of the saddles I've listed are absolutely perfect for some horses and riders - they fit well, and the pair performs beautifully in them. But if they're not, they're worth no more to the individual horse and rider than the most humble old synthetic beater ... except in the mind of the Name Queen.