My experience so far is: don't go for the €100/$100 one.

I bought one because my relative wanted to have this particular model in his 3D printing... cave (for lack of a better word) and it broke down after a few weeks.

It's just starting to get early adopter traction in an early adopter country, so it'll probably be a while until you can find something locally.

https://www.rahatsmall.com/

http://www.livinghertz.com/

are apparently 2 popular consumer brands in Korea.

I just searched aliexpress for "ultrasonic food cleaner", they probably work but no idea how they compare.

https://www.aliexpress.com/item/4001039347867.html?spm=a2g0o...

I see some 10W models, 50W models and 100W models - how much power is appropriate?

Here is what I saw for an ultrasonic jewelry cleaner:

>As a general rule of thumb, you will require between 50watts to 100 watts per gallon for your ultrasonic jewelry cleaner to achieve efficient cleaning.