I just bought a pair from 拼多多 (Pinduoduo, a Chinese e-commerce platform) yesterday for 100 RMB (Approx. $13 USD) and just received today. The moment they made the first note, I laughed - and immediately regretted a purchase I made many years ago: my current only other pair of IEMs, the "QDC Fusion S", which I bought six years ago when I still believed in "Subjective sound impressions" and "Price represents sound quality". What I’m trying to say is, that the audio engineering industry has come a long way in these years - getting great sound has truly become much more affordable, and the standards for good sound have become far more transparent. Now, poorly tuned or non-cost-effective headphones have nowhere to hide. (No disrespect to QDC: just wild how much things have improved)