Buying chips in a free roll (kind of long)

First, a little setup. I was playing in a free roll tourny over this past weekend at my college. It was put on through my dorm and the winner got a $75 gift certificate while the runner up got a $20 gift certificate. One of the guys at my table was donking off his chips by going all in blind every hand because he had someplace to go. Miraculously, his hands were holding up and he quickly quadrupled up and was easily the chip leader of the tourny. He had to leave however, and didn't know what to do with his chips. I offered to buy his chips off of him for $5 knowing that I was better than 95% of the field and with the chips, I could easily win the tournament. He took the offer and gave me his chips giving me a huge chip advantage over the rest of the table/(field). I eventually went on to win the tourny and the gift certificate [img]/images/graemlins/cool.gif[/img] but I also caught some heat from my friends saying that I cheated by buying the chips.


My question is, was what I did un-ethical and bad etiquette? Do my friends have a valid point or are they just jealous? [img]/images/graemlins/confused.gif[/img]