99% of games are over-priced and some devs/publishers, particularly those who take a 'release now patch later' or 'don't put it on the disc, make it DLC so not everyone can have it and we extort more from the gamers' attitudes so in those circumstances I believe pirate away. Also, if you are poor and cannot afford games piracy may be your only option.
Long story short: Piracy FTW







