How much does a drag chute system weight?
It depends on the aircraft- for example, the the brake parachute system of the 17t F-16 weighs 20 lbs. 

Generally, in an aircraft the brake chute system will weigh much less compared to the thrust reverser. While I'm not able to get any 'official values', according to this thres,


  In a Lear (24-25) the drag chute weighs some 25 lbs, the Dee Howard reversers weigh 350 lbs...