The problem is, buying a gun from a trader feels so... unorganic. So you made some ezpz quests, have way too many dukes way too fast, and suddenly you have a gun that enables you to rush through the content for dozens of hours before it becomes any harder.
Honestly with the new emphasis on slow progression, I feel like the old gun parts system would be more than welcome. Steadily find parts to assemble your gun piece by piece, until "tada", you got the last one and can finally make use of it. Traders could sell parts only instead of selling complete guns, and suddenly the whole experience of advancing to the gun stage becomes smooth, instead of a sudden drop.