There are some brands of bicycles that can cost more than the down payment on a car. Why? Surely making a bike lightweight and reliable isn't so difficult that it warrants that price? Is it just the brand name or maybe it has to do with customization options?
As people dive deeper into a hobby they have very particular desires. That means two things: (1) specialty parts with very low sales volumes, and (2) people are willing to pay extra to get exactly what they want. If I just want two wheels and a set of pedals and don't really care about the details then I can grab any $200 bike from a department store. But if I want, say, a very particular drivetrain, carbon fiber parts to shave weight, maybe a specific suspension design, mounting points for niche accessories, etc., then I'm shopping for very specific items from boutique brands. That's why a very small number of hardcore riders do crazy stuff like pay over $4k for a set of wheels.
You'll see the same thing in other hobbies, too. I can't imagine what some people spend on their gaming PCs.
$1500 gets you a pretty kickass gaming PC, even if it's not absolute top of the line.
In mountain biking, $1500 gets you a solid hard tail or an entry-level full suspension from a direct-to-consumer brand like Polygon if you're buying new.
Right, but that's top of the line stuff. You can easily build a PC with a 70 tier GPU for less than $1500 and you'll still have a kickass gaming PC.
The XX70 tier equivalent mountain bikes cost like $3000-$3500. I'm thinking along the lines of a Trek Remedy 7 (which is what I have), a base Santa Cruz Bronson, or a base Specialized Stumpjumper. There are plenty more but those are just 3 from some big brands.
The amount you spend also scales with how much you want to use the device, and the quality. It's similar with power tools.
£100 combi drill? For the average DIY user, exactly the same functionality as a £500 one.
For a tradesman using it 7 hours a day, 240 days a year, the more comfortable/reliable one may well pay for itself.
This does sum it up pretty well, but bike pricing in general has gotten out of hand and pretty much everyone in the biking (specifically mountain biking) community agrees. Of course, volumes are pretty low for these products.
Just the frames for many of the higher end models can be $3000-5000. A fork is another $600-$1600. Shock is $500-1000. Carbon wheels are like $1500-2500 (alloy more like $500-800). Tires cost as much as cheap car tires, around $100 each. Pedals can be anywhere from $20 to $250. The new wireless drivetrains (made up of fragile derailleurs, crank arms, and cassettes/chains which importantly are consumable wear items) from Sram are just absolutely insane at like $1000-2500, Shimano has much more reasonable options from like $300-$1500 at the high end. Brakes (more expensive usually means more powerful) range anywhere from $200 a set at the low end, to $1000+ at the high end. Then there's handlebar, stem, spacers, tire sealant, valve stems, and other misc bits.