Shattered Kingdoms

Yeah it only requires you buy 100 so you can get 5 double weak heal vials.

It seems like the issue isn't just incentive, but providing enough incentive to a likely loser of PK. Considering the four Bartlett types, appealing to Explorers and Socializers seems the most likely. Achievers aren't much into losing stuff, and Killers aren't much into badly planned attacks.

Explorers can find appeal in losing if it's a productive learning experience. So PK strategies can't be static. We can't expect tons of mechanics changes, but regular re-jiggering of equipment might do the trick. Achievers and vets may not be thrilled with that. However, adding uncertainty also helps with the Killer's fundamental objection that going against a better-prepped opponent is more foolish than fun. Maybe it's worth it.

Socializers can find appeal in losing if there's an expectation of a social or roleplay payoff. The good news is that doesn't require a mechanics change to happen, but it would require a culture change. Last time I was posting here, even Dulrik was saying tribunal members have an obligation to be free targets for PK groups. That plotline doesn't take long to get old, and the game's leveling is already a turnoff for Socializers. There's also the problem that fountain-RP Socializers may not be challenging enough for Killers to particularly enjoy.

Of the two, I think Explorer variety-in-combat is most in keeping with SK's focus and current players, but your mileage may vary.

This is, again, simply not accurate. A protip for everyone who wants to convince Dulrik that X or Y thing needs to be changed is to make sure you are arguing based off of fact. In fact, there is very little difference between the worst strong vials and the best weak vials.