I'd ask them why, I'm sure they can explain it. My initial thought is that when you powder fruiting bodies (mushrooms) the weight is effectively divided by 10 4

I'd ask them why, I'm sure they can explain it. My initial thought is that when you powder fruiting bodies (mushrooms) the weight is effectively divided by 10 4oz (113g?) of dried powder probably has 40oz (1.3kg) of input. By the time you add in processing and packaging who knows what the cost is. I know I looked at what you could realistically charge to restaurants in the UK and it was somewhere around £15 a kilo. This is why I'd prefer to eat the thing, rather than a product of the thing. Ask them - see what they say. I'd be surprised if they didn't explain it.