Not directly related, but is lowballing hard considered scamming? I.e. if I offer $10M for a Kyu Hat or something along these lines, and they accept my offer immediately. My understanding is that scamming would involve someone attempting to convince someone to give something away or sell for very cheap via social engineering? Lowballing should *always* be fine.. right?
Related to the actual topic:
All profit that comes from buying/selling barring long-time investments is done by taking advantage of other people's mistakes. Buy low, sell high, that's just capitalism. To have a truly fair trade system, all items and Pokemon would have to have a fixed value, but nobody wants that.