What is the opinion of Reddit about the
Solidtek Bilingual German English Black USB Wired Computer Keyboard?

This is not a gaming keyboard, but affordable and available on Amazon.com:
https://www.amazon.com/Solidtek-Bilingual-English-Computer-Keyboard/dp/B07KTC7X66/ref=sr_1_3?dchild=1&keywords=qwertz+keyboard&qid=1606077634&sr=8-3

German keyboard layout is also called “QWERTZ”, you may have better luck using this as a search word.
Otherwise: Seconding stickers.
https://www.amazon.com/KEYBOARD-LETTERING-TRANSPARENT-COMPUTER-LAPTOPS/dp/B002Q6ZTLQ