ok - easy to put up a post stating vague generalities about this and that calling out or insinuating someone is dishonourable.
Could be he owes her $50.00 - is it really worth whining about? move on
True though, if it is substantial (over $500.00), then yes you could expect it back and likely have a legal stand to do just that, again - move on.
We also don't know the agreement and maybe the purchase was requested as a prelude to something they were both going to do and enjoy - the falling out of the relationship negates it then, doesn't it.
Bottom line - you agreed to purchase it and then things fell through which means things changed and original expectations are no longer in place - only you know the full story but chose to post it vaguely.
A lot of supposition and speculation to make someone look bad *shakes head*.