Support weapons have pretty much always been my primary weapon. I don't much care for the extended blast radius of the new rocket as it's easier to hit multiple mobs at once. I finished all stages of prots using a SGA rocket and the eco...well wasn't great. There are a lot of things to consider though with rocket hunting. You pay MU on ammo but you don't pay for armor decay, amp decay, and fap decay. Also the skills you get from rocket hunting still have decent value if you choose to sell. I've chipped out plenty of support and explosive skills when I ran into hard times.
It's kind of crappy that they have the high reqs for the Negator. The rocket is going to be limited on who can actually use. Not cheap to chip up to these levels and extremely expensive to skill to it. The weapon is very situational to most people. Rocket hunting takes a lot of creativity but if you can manage to learn all the mob hitboxes, it's very fun. For someone that wants to hunt mobs way above their skill level without buying high-end armor, gun, amp, and fap. Rockets are definitely an option. As a complete noob like myself, I've been able to hunt the following naked;
Prots
Grand Formidon
Malc
Osseo
Chompers
Levi
Dasp (with one death per mob)
Most mobs you can have their health far below half before they even reach you if you don't want to run from them. I wouldn't sell these rockets for under 10k. As someone that can actually use the Negator, I think 10k is a steal. Unfortunately, I don't think most people are stupid enough as me to skill rockets this high.