If PA could be obtainable, it shuld be VERY VERY limited, like in UbiValkin idea.
Or we could make it EXTREMELY hard to get, as some kind of ultimate achievement for those who achieved everything else.
For example it would be craftable by a lvl3 armourer with at least 200 repair. The parts would contain of:
-one special, unbuyable, uncraftable part - i.e enchanced alloys, which would be given by the GMs as a sort of reward for making a special quest, winning a contest or sth like that (that would limit the number of available PAs to whatever number the GMs would find reasonable)
-one extremely expensive, uncartable part (i.e. hydraulic (?) suppor system) to be bought for some insane price (100 000caps? I've always avoided bigger gangs, so I'm not aware what is their idea of an 'insane price')
-two parts that would be obtainable only by killing mobs that wear PA (or APA) - remains of a Powered Armor and damaged PA battery. Thet could be randomly (and rarely) spawned in the corpse of a Brotherhood or Enclave soldier - you should have to destroy a few patrols to get those.
-one part that could be made only by the Doctor profession lvl3 with at least 150doctor- hydraulic biofluid
-one part that could be made only by Bigguner profession lvl3 with at least 140repair and 120 science - PA microengine (made from combining 3 evanger minigun engines, thus requires 3 avenger miniguns to waste ;])
-one part that could be made only by Energy Expert lvl3 with 130 science - internal PA battery - made by repairing damaged PA battery with some parts from 2 Plasma rifles (so you have to have a 2-3 plasma rifles to waste on that) and fueling that with micro fussion cells
-one part that could be made only by an armourer lvl 3 with 190 repair - exoskeleton made from certain parts from 3 brotherhood CAs
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Heh, I would implement some requirements for parts craftable only by SG and demolition lvl3 experts, but couldn't think of any ;]
I hope you understand my idea of crafting Power Armor. It should be a kind of an Ultimate Achievement, more a matter of prestige than of actual practical advantantage it could give. This will be sth like: If a gang maneged to craft a PA, then they actually achieved EVERYTHING that this game has to offer. I would be like:
<A guy from gang X wearing PA enters NCR with an escort of 5 fellow gangmembers in CA armed to the teeth>
reaction:
'OMG WTF, O RLY, JESUS CHRIST, THEY ACTUALLY MADE A GODDAMN POWER ARMOR?!?!?!?!?!?!?'
;]