Tell me again, why does this matter?
Credits are credits.
....
You are given incomes and expenditures in the books - just use those and forget dollars.
Your point is well taken, but Kyron has a point as well.
CT is certainly a game that encourages players and GMs to "make up" what they need in the game. So, a player comes to the GM and says he wants one of those gizmos that straps to your arm and slides a small pistol into your hand when the device is triggered. The PC wants to conceal it under his clothes.
Well, there's nothing quite like that in the game. Yet, it exists, at a fairly low tech level, too.
So...how much is it?
One could use a version of the "Holsters and Accessories" rule, which says these items are usually 10-20% of the weapon. In this case, maybe make it 25-30% and be done with it.
But...in this day an age...the crafty player comes to the game with a picture of such a device he printed off from some supply store on the net. The device is made of plastic, so it won't be detected with metal detectors, and it runs $999.
What! Four of them = a ground car!?
See..we're thinking in 2009 terms.
In this example, it helps to know the purchasing power of a credit. To be accurate, we'd have to figure what the device would cost in 1977.
Personally, I wouldn't make it that complicated. I'd just use the 25-30% quicky and be done with it.
Still, though, say your player has his character walking through a bazaar on a world and picks up a purple, egg-like thing. The natives love them. They eat them, and they are, indeed, eggs.
How much?
The GM things about a carton of eggs today and says that they cost Cr2 credits.
What the GM should do, to be a little more accurate, is estimate what the eggs cost in 1977.
Say they cost Cr1 for two cartons. Spend Cr2 and get the fifth carton free.