Ok - I would state that the item is use activated in the passive sense
The Lifesaver:
(insert description here) This item will bring into effect a cure light wounds spell as cast by a cleric of level X upon the bearer/wearer of the item once per day whenever they begin to bleed to death. (Game mechanic definition of this is when their hp total first drops to between -1 and -9)
Prereq Contingency, cure light wounds, Item Creation Feat
True Item Caster level = 11th
Market price
Cure Light wounds - caster level 1 26,800gp
Cure Light wounds - caster level 2 27,200gp
Cure Light wounds - caster level 3 27,600gp
Cure Light wounds - caster level 4 28,000gp
Cure Light wounds - caster level 5 28,400gp
Cost to create (in order)
13,400 gp + 1072xp
13,600 gp + 1088xp
13,800 gp + 1104xp
14,000 gp + 1120xp
14,200 gp + 1136xp
Notes:
The market price varies directly with the caster level of the CLW spell the item brings into effect. The cost is higher really for two particular reasons. First off, unlike the periapt, this thing can heal you instantaneoulsy - and possibly get you back into the battle. Secondarily, unlike the vest of false life - these are actual hit points, IIRC about the vest.
Not too much for a fairly valulable life insurance policy I would think.
If the item doesn't take up a slot (ie it isn't a neclace or what not) double all costs given.