Even less than Knox:
Studebaker Vinyl Record Cleaning System with Cleaning Solution and Soft Pads Included at $42.50 on 2/21/22
Amazon product ASIN B01GOOAEVK
My experience with cleaning records:
I started buying records in the late 70s, early 80s. Never cleaned them until college (mid-80s) and I just dusted them off with a soft cloth.
At the college radio station I was introduced to the Discwasher D4 wooden handle with felt pad, and cleaning fluid. We were told to clean every record before we played it. At home I used one of those carbon fiber/felt brush cleaners before each spin.
I didn't buy any dedicated cleaner until about 8 years ago, when I got a spray bottle of cleaner and a soft cloth packaged as a kit. Worked pretty well for doing occasional cleaning. Didn't get gunk out of the grooves on used/dirty records, though. And I started buying more at flea markets and bargain bins.
I was skeptical of the Spin-Clean, too. $70 for a plastic tub and brushes and fluid? But then I got an open-box deal on Amazon with a gift card, and noted it was designed and built in Pennsylvania (where I live), so I felt better about supporting a local/stateside company, paying a US laborer. At least that's how I justified the expense, haha!
The Spin-Clean does a really good job. It's just time-consuming when you have to clean something like 40 records. It's all manual, and my cloths got wet drying the LPs (I did not air dry in a rack) so I was limited to how many I could do in a sitting. I used that for quite a few years.
Just got the VEVOR unit mentioned here, direct from their website. Found a coupon that brought it under $210 shipped. Instructions were non-existent, the spinner add-on is a bit kludgey, but the results have been great. I can do 4 at a time in a 20-minute cycle, hands-off other than swapping them and drying them after. Much more time-efficient if I have a bunch to clean.
Since I re-sell to support my hobby/obsession, this has helped me with grading and offering the best used records I can to my buyers.
When people spend thousands on records and gear, a $200 ultrasonic unit doesn't seem excessive in the big picture. Even a $650 iSonic is a worthwhile investment. I have 2 friends who got this model and they love it. It's a little quieter than mine.
iSonic P4875II+MVR10 Motorized Ultrasonic Vinyl Record Cleaner, 110V (10-Records)
Amazon product ASIN B07PT6HRNQ