During the stream (and in the patch notes), it was mentioned that the supply cost will go up as characters level up. It stays at 40 throughout the Chapter 1 and levels 1-4 though. Is it going to go up once we hit the big milestone levels (5, 11)?
It is also somewhat strange that the cost stays the same no matter how many characters are in the party. Perhaps it should be 40 per character rather than 40 for the whole party, and something like +20 at the aforementioned levels? I didn't exactly spam camps, and I am at well over 300 units of food (4 or so supply packs and all the random stuff picked up in the environment) in 6 hours of gameplay, which aren't gonna run out any time soon, so there doesn't seem to be much of a limitation there so far. But it's going in a right direction.
Weirdly, increasing the cost based on how many people are at camp is something I like. It'd move us away from anything indicating a blanket wiping of companions because the more companions we have the greater cost of maintaining them, adding a balance where having too many on hand can be hard on resources.