Tl;DR: weapons could sell for more to traders based on how many kills it has achieved.

Guns should sell for more depending on how many pmcs/scavs it has gotten. So after a few good runs you could retire some of your weapons for a decent return or risk getting it higher.

Lore wise these weapons would be "Battle Tested" or some kind of status like that.

It could help even the trader usage. For example, maybe skier pays more for weapons with scav kills and mechanic pays more for pmc kills.

This gives the players incentives for more aggressive playstyles because people would be trying to get enough kills for their gun so they could eventually trade it in.

What do you think?