As soon as I can get in the fleet, I'll throw in a few hundred k.
Also, you can get every type of standard (not large) battery for 200ec at any ship requisition station that sells consumables. And you can get engine and auxiliary batteries for 40~100ec each on the exchange.
As to crafting, I would recommend checking the exchange for the high tier weapon/thing you want versus how many uncommon unreplecatable materials it costs. I found while leveling that the cost of materials sometimes ended up being higher than the cost of just buying the Mk XI Very Rare weapons.