You would never give willingly money to the stranger.
I believe that whole concept of being beggar could a little bit disagree with you.

Also, it depends on how do you see it ... it could be seen as investment ...
Doing some favour would be better, i agree ... but it should be working by quest, or previous mentioning like: "Oh please i desperatly need a hammer wanderer, if you find some, bring it to me please and i will offer you a discount as reward."
Right now its more like "Hey here is some junk i found, i presume that some of it could be valuable for you, so give me a discount." or "Hey, here is some junk i found. > But this is not a junk wanderer, this hammer is priceless for me! > Oh yeah? How priceless? > Incredibly priceless, i need it desperatly. > Fine, keep it, for free. > May i offer you a discount that will cut all mine profits in half? > Ok, sure. *feeling so altruistic, while i just exploited needs of others for my own profit*"
If you have no reason to give someone 100g, how could you have reason to give him for free some hammer that is worth 100g for him?
I just dont see any difference.
Yes, i know that hammer would have zero value for hammersmith with kazilion hammers on his shop ... that is why you didnt bringed it to him, but to this other person, who desperatly need a hammer. :-/ Yet, that otherwise worthless hammer is valuable right now, right here ... that is why water costs so much in middle of desert, and so little next to huge lake ... so, where is difference?