Cooler Master CK550 V2

“Hey, I am looking into buying a new keyboard as some of the keys on my Cooler Master CK550 V2 have been skipping inputs and it is getting pretty annoying. I am looking into getting a full (or alternatively 96%) keyboard with ideally these features: preferably under 150€ (I am fine with buying second-hand), brown switches (i.e., tactile and quiet), backlight (not a necessity, both RGB and monochrome are fine, I don't care about the backlight being programmable) as well as "tame" colouring (i.e., I prefer my keyboard to look "boring" instead of something like what most Ducky keyboards seem to look like). It should additionally be available in Europe/Germany (I looked into getting a Ducky or a Keychron but the models that I like seem to be out of stock). I use the US keyboard layout (ideally I would prefer the ISO layout, i.e. US international, but it's probably the least important thing that I have listed here). Regarding this, the Das Keyboard 6 Professional looks nice (at least in theory, I am aware that they aren't well-liked here) and I saw that someone is selling it second-hand (apparently only opened and not used) for around 100€. Is that a good deal? Thank you for your help.”