Flohmarkt? Seems simple enough.

That’s only useful in commit messages, issue discussions and stuff like that. Why would the devs even make that execute in source files, where it’s all but guaranteed to be a false match??

A few of things I’d look out for:

• Bluetooth protocol. Many Bluetooth headsets switch to a low-bandwidth but full-duplex mode when used as a headset. As a result you can hear and be heard at the same time, but at abysmal quality. Think old phone. You want a headset that supports at least AptX, which supports full-duplex communication at reasonable bandwidth and thus quality.
• Spatial audio. Don’t bother! It’s a non-issue that you can replicate in software, with the help of pipewire. I wouldn’t spend money on it.
• I’d stay away from proprietary 2.4GHz connectors and stick with plain Bluetooth, as that doesn’t require a specialised driver that possibly requires support from the vendor.