when making a plug-in and adding ships, outfits, etc. how do you come up with the cost for it? just a random number or is their some kind of chart or something you go by?

and also, with ships, how do you decide on the fuel, armor, shields, etc. to give it?

Basically, you just take a look at various existing ships in EVN, find ones which are sorta similar to yours (as in if you're adding civilian ships don't go looking at polaris ships for inspiration) and try and come up with a good balance of price and stats for your own ship that fit in reasonably with the existing ones.