Payload designations such as 1/2-ton, 3/4-ton, and 1-ton are little but nods to the past practice of naming a truck according to its actual payload, and don't accurately describe total or per-axle payloads. The payload range I've seen for a 1/2-ton is 1500 to 2000 lbs depending on engine, axle ratio, and cab options with curb wts of 4500 to 5400 lbs. 3/4 and 1-ton pickups can carry far more than their name would suggest. A 3/4-ton Reg Cab Chevy with a GVWR of 10000 lbs can carry 4212 lbs in addition to its wet curb weight of 5788 lbs. A 3/4-ton Crew Cab has a max payload of 3247 lbs with a curb wt of 6253 lbs. A Chev dual rear wheel 1-ton gasser has GVWR somewhere north of 13000 lbs and rear axle rating of 9825 lbs (the two extra tires allow for the extra weight), which gives them a maximum payload of up to 6900 lbs.
An equally outfitted 1/2-ton and 3/4-ton has a MSRP price diff of about $1600. For medium duty towing(5000 to 8000 lbs), I'm putting my money on a 3/4-ton.