Shouldn't it be the other way around? If someone pays me first then they wouldn't have a chance to scam so I can't judge their trustworthiness. However if I pay first and they deliver (or I deliver first and they pay later) while having a chance of scamming me - that proves trustworthiness, at least up to the value of the deal / risked amount.
That's a good point, but I also look at it this way. If someone has enough btc to pay me upfront for an item and share me their shipping details, and has a decent rep in collectibles or is anewbie who is actually trying to learn/get ahead, (without any shenanigans or feelings of unease), and I deliver and they are happy, I see that as fairly trustworthy, as ofc I have no reason to get scammed, nor would I scam anyone as most people who really know me know. To be fair/honest, sometimes I never leave trust in this scenario, and sometimes I do if it's a high-value item or something "different", so I don't think I've ever enabled any scammery in this manner .... I will think more about this as well.
As for the second scenario, yes, it indeed does prove trustworthiness, and I usually put trust on those deals ahead of the former. However, I have not been part of many deals where half is first/half later for some strange reason.
