I don't really like plastic bags for several reasons... the first is that static thing that always happens with plastic bags... every put some kill in a ziplock baggy than after you smoke it all, you look in the bag and you see all of those lovely trics stuck either in the corner of the baggies or simply on the sides of it?? such a waste imo, lol.. one reason why glass is much better for curing..
and like said above, you buy some nice glass jars once and so long as you take care of them they will last for years and years...
also, i don't think that ziplocks are really all that odor proof.. i don't know how many times i've had some kill in a ziplock bag and you could still smell that bud down the street.. put that same bud in a glass jar, and the odor pretty much goes away ime...