In my opinion, they should (to the least) up the durability of the next tier by 100%, and maybe lower the stone tier durability by 50%.
That way you have something which is "better" which breaks every time, versus something that's slightly worse, but that you have to repair once a day.
That's also kind of realistic, isn't it?
After all, it's like fighting zombies with sticks, or fighting them with a durable, full steel, machete.
Durability is not an issue in this game, especially for stone stuff. It's a near instant repair that costs 1 of very easy stuff to get. I would only be skeptical of using something if they required parts to repair, but if I'm not mistaken, nearly everything is repaired with the repair kit. Though I do agree that the difference should be more radical like you said.
I do think there's a middle ground, like meganoth said, there could be a tier damage value nerf, or like riamus said, have more specific requirements for mods.
To be fair, I agree with both of their ideas. And I personally would handle the situation like this:
1. Have the quality disparity/requirements increase based on tier:
- Stone tools would require 10 magazines to reach max quality, while the following tiers would require exponentially more.
- However, also make the qualities have different percentage gains based on tier +3%/5%/7%
- This makes sure that stone tools are average all around (as they should) and the max tier has significant upgrades between qualities, which also take longer to reach, extending the endgame and buffing the early game to mid game progression by getting into tier 2 weapons.
2. Rebalance mods to tie with both quality and tier:
- Stone 1-2 quality would not allow any mods, while 3-4 quality allows 1 and 5 quality would allow 2
- Iron 1-2 quality would allow 1 mod, 3-4 quality allows 2, and 5 quality allows 3
- Steel 1-2 quality allows 2, 3-4 quality allows 3, 5 quality allows 4
- Quality 6 weapons would allow 4 at all times to prevent people from not being able to use their favorite gun (4 is the max right? genuinely can't remember)
Something along these lines, I just wrote this in a few minutes, but each weapon be it tier or quality, would feel very different from each other.