For me, the value of items depends on whether or not the promotions involve intense micromanagement. For instance, one of the promotions you mention is Fur Coat which prevents Blizzard Damage. If the Fur Coat requires Fur (and a Tailor?), but is automatically awarded to any new units built in that city, then go ahead. On the other hand, if every time I build a unit I need to remember to cast the "Make Fur Coat spell (cost 2 Gold)" and then tell the unit to "Use Fur Coat" then that's a layer of micromanagement hell I could quite happily play without.