Indeed,
@yixiaojiu is quite correct; the vast majority of individuals offering cryptocurrency wallets for sale, approximately 99.99%, are engaging in fraudulent activities.
Nevertheless, there are instances where certain individuals offer wallets they are aware they cannot access. For example, it is not unusual for an individual have compromised to possess an account on a cryptocurrency exchange, like Binance. However, merely being in possession of the account holder's name and password proves insufficient. Consequently, some guys may attempt to sell such accounts, particularly in large quantities.
However, it is exceedingly difficult to find a trustworthy individual engaged in such practices. My extensive experience, I have only encountered one friend who sold a Bitcoin wallet containing a substantial sum of money due to their requirement for liquid assets. At the time, the Bitcoin in question was under investigation by law enforcement for its involvement in criminal activities. But, this remains the sole instance I am aware of, and as previously mentioned, +99.99% of these offers are entirely fraudulent.