I haven't tossed mine, and I get where you're coming from. Ultimately, neither of us know what the asker had in mind by 'worth it', but for the cost I wouldn't consider it a practical choice for most people. Unless you're on DRK all the time and doing a lot of low end content with suboptimal groups, it's just plain not going to get used. To get that value, you need to be in a suboptimal group, something has to go wrong, and everything else has to line up so that you being able to stay alive actually changes something.
If you enjoy DRK and want to solo on DRK, that'd be the best case for getting your gil's worth. But, if you just want a strong solo job.. not the easiest or the strongest option for that either.
The prime gun WS does not have the enmity mechanics the relic WS does which is the only reason you'd use relic gun in the first place.
Has someone actually tested this? Searching terminus in the prime thread has a lot of people speculating about it, but I can't find anyone testifying that it clearly does or doesn't, much less testing under controlled conditions. Enmity-50 on the bullet is also pretty considerable (you don't need to stay at extremely low enmity unless hate resets are involved, you just have to stay below VE cap).