Why are record cleaners so expensive?

Perhaps the question, reframed, is "I have a modest record cleaning system (X and Y) that I’m happy with, but wonder if those expensive record cleaning machines are really that much better and worth the money?"
A little less antagonistic, particularly since you seem to acknowledge that one can spend money on handcrafted or bespoke items that have importance to the buyer.
Most folks are allergic to hype, and I’m not going to tell you that veils were lifted or the orchestra was in the room. What I will tell you is that I’ve spent a fair amount of time and money messing around with various record cleaning methods, machines and techniques and not only have a lot of records, but some very valuable ones. I can get a record very clean using a basic VPI. But some records, particularly older records that have been exposed to who knows what, require multiple cleanings, and in my experience, multiple approaches. That’s where the combo of a couple different devices, including ultrasonic, starts to pay off.
If you don’t think it’s silly to spend money on a suit, a fishing rod or a vacation, why would you think it’s crazy to spend 3 grand on an RCM? (which, as noted, you don’t have to do if you are willing to go the semi-DIY route).

Why are record cleaners so expensive?

Simple economics 101, Supply, Demand and Price.   

@whart Look, man, there was no antagonism implied or intended. Especially not if people are going to get bent out of shape over a question about a mechanical device.

"Most folks are allergic to hype, and I’m not going to tell you that veils were lifted or the orchestra was in the room. What I will tell you is that I’ve spent a fair amount of time and money messing around with various record cleaning methods, machines and techniques and not only have a lot of records, but some very valuable ones. I can get a record very clean using a basic VPI. But some records, particularly older records that have been exposed to who knows what, require multiple cleanings, and in my experience, multiple approaches. That’s where the combo of a couple different devices, including ultrasonic, starts to pay off."

There - that's what I was looking for in the first place - that and @mapman 's earlier take.

As for the suit, fly rod, and vacation - those are all objects or experiences custom made for one person only (or a couple, in the case of the latter) and not really suited for anyone else. That's a far cry from a mass-produced (relatively speaking) cleaning device.

I probably will invest in a VPI once my collection approaches a decent number.

I got an early HW-17 on ebay for around 250.00

has it worked?  yes saved a number of records

has it paid itself off   not really :)

The price it takes to buy a used (or even new) VPI HW-16.5 will get you perhaps as good a record cleaner as you need. Far better than a Spin-Clean and far cheaper than an ultrasonic cleaner.