Sam, you’re weighing the losses, but that not the reason for the chilluk you quote; borrowing seforim today is not considered to cause a loss (shava pruta) at all.
HaLeiVi, you are making the claim (to defend Rashi) that yaavor v’al yehoreg doesn’t apply to beim adam lachaveiro. This is in fact what the Binyan Tzion says. I wouldn’t say it precisely the way you did, though, because at the end of the day, Hashem is the baalim on that as well. Maybe it’s a good enough sevara to be a pircha on a man matzinu, though.
R’ Moshe rejects this, though, because why would a person’s life be any better than his money, and we need a limud for r’tzicha.
Binyan Tzion bavorned this, though, and says ein hochi nami, but we need a limud for a case of mechilah, which surely works for money, but doesn’t for r’tzichah.