Hey all, thanks for your replies.
I checked my copy of Drow of the Underdark, and while they have them, there's no real solid text on prices and what not.
What I am looking for is more flavor text, as the player picked out a picture for his guy, which he based the guy on, but missed seeing the guy had a replacement arm, he thought it was a glove/bracer thing when he chose the picture.
In any event, the pic is neat and I don't have a problem "just giving it" to him as a no-bonus-to-anything-flavor-text-thing, but it did get me to thinking about it in general and should something happen in a game, I wanted to have an answer of somekind from a rules perspective.
What I am now looking at is D20 Future. (I had heard that there was a conversion note of multiplying the purchase DC by itself and then multiplying that number by 25 to get around the GP values.) If that is the case, a replacement arm, that gives no bonuses, would be about 7,000 - 8,000 gp.
I'm gonna take a look at Iron Kingdoms, see if it has any insight to offer.
Thanks again, everyone.