Solotripper has it right with the potential for leakage, don't forget the residual fuel in stove too. I carry the stoves and fuel bottles in a roll top sealine bag. The bag then gets hung on the pack with a carabiner on the portages and in the boat when on the water. Still run the old MSR bottles as that are remnants to my backpacking days. The sealine was a second that I picked up for a good price. Actually picked a couple of them up 20 years ago and first was finally retired last year as it doesn't hold air any longer. I agree the MSR bottles have gotten expensive, lucky I made the plunge years ago.