Incidentally, the portable nature of larger heaters makes them useful on expeditions in the wilderness unlesss a vehicle is available to transport them.  Lugging around heavy propane heaters and propane tanks is generally more effort than its worth if you have to transport them manually.  A simple campfire can make an excellent alternative.  

That said, the Sarejevo experience proves that propane heaters were in high demand in times of short supply.  If you want to take this route, then it is best to get them while they are available.  Afterwords, a luxury of this nature will cost dearly.   For warming a partailly enclosed space, the heater head is a great asset and potentially a life saver.