When I first installed a softener at a 4/2 wash I bought ten years ago, I softened everything. Salt was less than $3/bag then. Going through 20-25 bags a month wasn't a big deal. But now the price of salt has doubled. On top of that it is a hassle to load the brine tank.
Like many others here I have tried to get more efficient in operations. I just recently re-plumbed my high pressure autos to use hard water rinse. I still use soft water on all chemicals and the SS. The only reason I am using it on SS is there is no quick way to replumb. With the autos on hard rinse, salt usage is down probably 75%. I can not tell a difference in wash quality. You can argue that I may have more scale and hardness build up on the walls and equipment, but IMO for the cost savings it is worth it. If you are plumbed for hard water rise I would try it.
You can also check your softeners and see if you can extend the regeneration time. I assume you do regenerate based on flow. Go in and check hardness just before the softener generates and see if the water is still soft. If so, take a grain of hardness off the programming. In other words adjust your input water feed from (I assume from your post)14 to 13 grains. This will increase the volume of water between regenerations about eight percent. When it gets ready to regenerate again, repeat the procedure. Continue this procedure until you finally check it and it is hard just prior to regeneration. When that happens go back "up" one grain on your programming.
There are other things you can do to minimize salt usage. Frequent regeneration is supposedly more efficient if you make the necessary adjustments in the settings to reduce brine usage, but I just usually leave that set to default. I've never tried it so can't comment. You may want to look into that.