I tend to assume that 1 Cr = US$2.50 (c. 2008) FWIW.
However, there is no way ... NONE ... of realistically valuing the Credit in terms of early 21st century buying power because the absolute and relative value of the cost of production of items will have changed massively over the time period (and tech development period) in question.
For example, during the pre-modern period (right through to the beginnings of the Agricultural Revolution in the Low Countries in the 17th century), agriculture (we're talking Europe here, not Asia) was so inefficient and labour intensive that the relative cost of food was far, far higher than it is today ... the average worker spent in excess of 60% of their weekly income on barely enough food to keep alive ... which is why even minor variations in crop yield were regarded as "famines" ... and the need for food is price inflexible. They couldn't eat any less unless they were prepared to starve (and they did ... that's why these relatively minor crop yield variations were famines after all).
In the modern world? The oughties? I believe, from memory, that food (and we have a much higher calorie diet which consists of lucury foods that the average pre-modern worker could rarely, if ever, have afforded) consist of less than or around 5% of average income.
This is because agricultural technology has made the actual growing of things more efficient (yields have increased from 3 or 4:1 in later Medieval times to in excess of 50:1 in modern times, often far in excess) and this can now be achieved with vastly less labour inputs.
How much does food cost in the Imperium (not restaurant meals, not fast food, but food bought fresh ... or at least unprepared ... at a market or grocer or whatever) at the level of a percentage of disposable income. The costs proposed in the Core Rules are probably too high compared to the income, for prepared food, but if you can buy unprepared food for probably no more than 1-2% (maybe less) of your disposable income, that would be realistic, I would suspect.
Another example -- one of the reasons that DnD has always annoyed me intensely -- metal weapons and armour during the Medieval period and their cost. In the Early Medieval (say 800-1100 AD) the cost was very high relative to income, even of the wealthy, for a number of reasons -- the mines that the Romans had used were mostly worked out (at levels accessible/above groundwater at the tech level the Medievals ... which was basically late Roman ... possessed), fuel (charcoal, from all the virgin forests of the Classical period ... rapidly being cut down for fuel and for land clearance as the Medieval period progressed) was more expensive (and coal wasn't usable until some smart chappie came up with the idea of coke, which wouldn't be for several hundred years more) than it had been during Roman times, and the technology of turning the ore into iron and then of working the iron was primitive, labour intensive, and costly.
Shoeing horses was problematic for most people, and expensive even for the wealthy. Swords were the weapon of the nobility (and often handed down from father to son) because they were extremely expensive (and almost all early medieval daggers are cut down from broken swords ... or broken swords [per myths and legends of the period] were often reforged ... you couldn't afford to waste the metal). Armour was mostly mail, awkwardly heavy and extremely time consuming and labour intensive to make, but using less metal than plate and, therefore, less expensive than plate.
This all changed quite dramatically around the late 11th century, as advances in technology (better bellows, for a start) dramatically reduced the relative cost of processing materials and resulted in less labour intensive production methods becoming viable. The result was a dramatic and rather quick drop in the cost of swords, armour and anything made of metal. Even mining tech improved somewhat (or, more accurately, people were prepared to invest more capital in dewatering mines through the existing labour intensive and time consuming techniques, because slight improvements in agriculture, metalworking and other technology meant there was more capital available) which helped the whole process.
DnD, however, to my eternal disgust, prices weapons based on lethality -- so a hunk of wood (a bow) costs more than a chunk of metal (a sword) whereas the reverse was always the case.
So, how does this effect Traveller? Well, food prices, as noted above, is one way. Manufactured goods will be another ... the longer a technology has been mature the lower the cost it will be even if there have been some improvements in it ...
Which means, for example, that the relaitive (though not absolute) cost of Anti-Grav vehicles should be dramatically reduced at Average Imperial as it is introduced at TL9 (and AI is TL13, IIRC). Flyers might cost 100,000 Cr at TL9, just like Cars cost a relative fortune before Henry Ford ... but, today? Well, Flyers, at TL13 should probably cost only a tenth of that ... 10k Cr (see the Tata Nano for what you can do with this sort of maturity of technology) ... even for those using the current generation, though not cutting edge, of gravitic tech.
And that's all without worrying about Von Neumann factories or nanotech.
That's my .02 centicredits worth, anyway. FWIW 8)
Phil
