The advice to experience these machines before you decide is very sound. If you know anyone who owns or sells a cleaning machine, try it out. Clean a record with it. As stated, online videos show the machine in action.
I wanted to offer another machine that I haven't seen mentioned. About 3 weeks ago I got the Degritter. I can not recommend it highly enough. Unfortunately, it is beyond your target price. But, if you have the ability to stretch, it is worth it. It is super easy to use, cleans both sides of the record at once, it's fully automated, drys as well as cleans, is very solidly built and software controlled with free updates.
I have owned a Hannl from Germany for a coupe of years. A very, very good machine, built to very high standards and excellent at cleaning records. But it is a chore to use. It has a counter-rotating brush that is fiddly to adjust, cleans one side at a time, requires your constant attention, vacuums but does not dry the record, etc. I'm keeping it because it will do a better job on really soiled records, but I never look forward to using it. One real plus is how quiet it is. Most vacuum machines are very loud.
The Degrtter on the other hand is a dream to use. Turn it on, set the cleaning level, insert the record, push start and it does the rest. It will beep when it is done. And when it is done you have a completely cleaned and dried record, ready to go.
Nothing is perfect. Aside from the cost (~$3k) there are a couple of things to know. The drying cycle is noisy so it is best used where it won't annoy yourself or others. The fan speed and drying time are user adjustable so you can slow the fan to reduce noise but it is a lot louder than the Hannl. I don't think it is louder than most vacuum machines though.
Second thing to know is common to all ultrasonic machines. Creating the cavitation needed to clean the groves heats the water. After several cleanings the machine needs to cool it down. Fortunately with the Degritter that process is automated. Even mid cleaning cycle, the machine will shift to a cool down mode until the water temp is within tolerance and then resumes cleaning. No additional action on your part.
Sorry for the long post and a recommendation well outside of your stated price target. All of the machines work, they clean records. Some are a bit more effective, but they all work. As @pgaulke60 noted though, the user experience is very different. Some of these cleaning machines/systems are very labor and time intensive. If money is a tighter resource than time, there are lots of less expensive options that simply require more time and attention to clean your records. For me time is in short supply so the more automated solution is a huge benefit.
Hopefully this is helpful.
