Did you look on http://www.rockauto.com" onclick="window.open(this.href);return false; ? I see rear rotors for an 03 Vibe from $10 to $73 each, depending on the brand and exacly the specs on the car.
Thomas
the "Mustang Guy"
1987 5.0 LX Mustang
2016 Mustang GT - current daily
2004 Satellite Vibe &
2009 Red Vibe GT -twin's cars
2003 Neptune Vibe GT - prior daily
2010 Red Vibe GT - RIP 6/16/14
2006 Platinum Vibe - son's car
advanceautoparts.com shows two rear brake rotors for an 03 Vibe GT, one for $34, the other for $42.
autozone.com shows one, for $33
pepboys.com has one for $33
Those sites have physical stores all over the place where I am. If they are not where you are, then you may have to pay shipping instead of picking them up at a store.
I did see a $225 AC Delco rear drum on Rock Auto, but there are many other cheaper ones too. No expensive rotors though beyond the $73 ones I saw. I would be Ok with any Wagner, Bendix or Raybestos brand brake parts since they are the old school aftermarket companies known for their brakes.
Thomas
the "Mustang Guy"
1987 5.0 LX Mustang
2016 Mustang GT - current daily
2004 Satellite Vibe &
2009 Red Vibe GT -twin's cars
2003 Neptune Vibe GT - prior daily
2010 Red Vibe GT - RIP 6/16/14
2006 Platinum Vibe - son's car