You are a trustee fór the poor and should treat their money at least as careful as yours, maybe more. Shmuel’s father would keep money hidden in 3 layers, 2 of his and the middle of yotomim, protecting them on both sides – from genavim and from water.
And it is easy to spend their money more efficient than your own, as there’s so much need … If you are buying house for yourself, you are limited to a neighborhood and your family members preferences. If you are looking to buy a house for poor people, you can invest where you can find a good property. If ny is overpriced, buy in Lakewood. If poor in Lakewood are getting free government food, buy food for poor in Florida. If you meet a person looking for help with a wedding, but looks suspicious, go to a gemach and find a worthy recipient. A possible argument against would be that Hashem sends you a mitzvah and you should do that rather than looking for a better one. So a need in front of you should have preference over slightly higher need in another place, as halakha says