No.
$10 for a single weapon is insane. Even if they were to go on sale, I have standards and principles and I'm not going to give up as a consumer on them because TWI is bad at handling their finances.
I'll still play the game, but I'll "Cheat" them into my game (if I feel like using them, I'll give them to myself). If they make it so you're forced to pay to use them, I'll just stop playing, simple as that.
Asking $10 for anything that isn't cosmetic DLC, when there are still dozens of issues not solved since release, is absolutely ridiculous. There are still RNG microtransaction lootcrates, there are still teleporting Zeds and over-aggressive Zed spawns, there are still insane balance issues with certain perks, Survivalist still exists as a "Perk-in-progress", there are still balancing issues with cross-perk weapons like the Tommygun, there are still balance issues with the upgrade system, there are still weapons missing from KF1, there are still missing aspects of the game like the ability to actually see any of the purchasable cosmetics in-game if you don't own them, and as nice as the 3 weapon re-tools are from a mechanic and gameplay perspective, giving SWAT a light blue automatic nailgun isn't going to make me want to spend $10 for another Gunslinger weapon.
Mods are almost impossible explicitly because TWI made it so, too. If I wanted DLC weapons, I'd play KF1, where, at the very least, I can get 4 weapons for $7.50, instead of 1 for $10.