You -- the global you here on MR, not a specific poster -- are displaying some interesting asssumptions around this scenario.
Assumption #1 - that the man is literally homeless -- as opposed to living in a residential hotel, with friends, in a shelter, or just maybe, in an actual house or apartment.
Assumption #2 - that the man has no money and would have to find, borrow or steal an iPod. As opposed to drawing a disability pension or other benefit, or collecting returnable bottles, or having a solid investment fund that pays him a few K per month.
Which leads to assumption 3, that a 'homeless beggar' was always a marginalized person who never earned an honest days wage... as opposed to - to cite an actual acquaintance of mine - a high school chemistry teacher for 20 years before deciding to opt out of the mainstream.
Which in turn leads to assumption #4 - that the man was forced into his current position, whatever you assume that to be -- that it isn't a matter of choice to have the ZZTop beard and to carry a collection of worldly goods with him.
Granted, many or even most people on the margins of society are there because of conditions such as loss of employment, or mental illness, or substance abuse. But as another acquaintance told me, he collects empty bottles because he just doesn't like the stress of the workplace. He makes an adequate living, and for him, he is happy with his choice.
Finally, there is assumption #5 - because you judge that this person is 'homeless' and 'poor', it becomes remarkable to you that he should have chosen to take $40 or more to invest in a good quality music player. Even to the point of thinking that he shouldn't have such a thing, that if he were more 'responsible' he might have used that asset for a haircut and shave, or to buy food, or... Why do you assume that you have the right to make personal choices, and he doesn't?
In the mean time, his iPod probably brings him hours of pleasure per day - strikes me as an excellent investment. Maybe he'll comment on this thread if he happens on it while downloading his latest batch of political science lectures and paleoanthropology podcasts from iTunesU on a computer at the public library.