Airport transfer groupon-what does a/r mean and is this a good deal

http://translate.google.com/translate?sl=auto&tl=en&u=http%3A//www.groupon.fr/deals/paris-extra/transportmail/5553217 It says 49 euros (instead of 180) transfer a/r up to 3 people or inner suburbs of Paris to roissy or orly. Does a/r mean round trip? Does this sound like a good deal instead of train to rue cler area from CDG?