Your Collection....back In Time

I really don't think there is any possible way to estimate that. No formulae is possible since there were so many variables in prices back then. Even in the early 1900's, prices of items varied so massively from place to place that an attempt to find one common method of determining that would be just a wild guess.
It may be difficult for many to understand how far we all have gone in the last 50 years even. For example indoor plumbing in many areas is as recent as the last 25 years or in some areas still not available. In the 1940's you could go to a local store and pay $0.05 for a loaf of bread but go to another area and pay $0.25 for the same loaf.
In the early 1940's Silver Dollars were common and spent as ordinary money. I remember doing that a lot back then. Not many coin collectors since we just came out of a massive depression so people had other things on their minds than collecting coins. Or anything.
A Morgan silver dollar was just a Dollar.
The problem here is those Dollars that were worth a Dollar could buy things for what may have been worth a Dollar. However, due to coin collecting, Morgan and almost any Silver Dollar has shy rocketed in value much more so than just inflation. Then too over time people have realized that some Morgan dollars are worth way more than others.
Today we have mingled in the inflation values, coin collecting values, mintage quantity values, Grading systems and Silver values so it is really not to easy to figure out anything for your 200 Dollars worth.

There absolutely is a way to estimate the purchasing power today of $200 in 1904 and Sap pointed out one such tool. You just need to retain the measurement unit of dollars and not start thinking in terms of individual products. The most commonly accepted answer to the question you posed? $200 in 1904 = about $5000 of 2010 purchasing power for "stuff" in general and ignoring the PM angle. That's with using the CPI as the key variable input per Sap's link. Yes, underlying assumptions could be argued, but since I do that 50 hours a week already, I won't enter the fray here.

Just to illustrate how thinking about individual products changes things, take the last 5 years. Oil was about $45 a barrel, compared to about $90 today. A big flat screen TV was about $1000, compared to under $500 today. Thus, a basket of goods approach that spans geographic areas yields better results.

Now, give us the dates and grades of those 200 Morgans and today's purchasing power is easily quantified.

It's not quite as simple as plugging numbers into a calculator might suggest. The question of how to calculate the impact of inflation is one that continues to vex economists and probably will continue to until the end of time. Serious issues that need to be considered are the changing mix of what people buy, and the changing quality of those goods and services.

For a gallon of milk, it's an easy comparison. A gallon of milk now is little different than the gallon of milk 50 years ago. You can compare prices directly.

But what about computers? The current CPI calculation assumes only year over year adjustments, with a guesstimate for quality factor. For one year over another, that might get close to right, but over the long term, completely breaks down. For instance, the processing power of the computer on which I type this response could not have been had for any amount of money 25 years ago. Conversely, if someone tried to sell a computer now with the horsepower that was available back then, he couldn't get any money for it whatsoever. Of course 100 years ago, no one spent any money on computers at all, since they didn't exist. How does one figure that into an inflation calculation?

Or take entertainment. Around the turn of the 19th/20th century, there was no TV. If you wanted entertainment you had to go to a show, which comparatively speaking was much more expensive than the one-time cost of a TV (even if you include the insane prices cable companies charge).

An average salary based comparison breaks down for this same reason - Back in 1904, average income might have been $400/year, but things like dishwashers, refrigerators, microwave ovens, and air conditioning didn't exist. Cars did, but were so cost-prohibitive as to effectively not exist. Electricity did too, but most didn't have access to it. Even running water, which we take for granted, didn't exist in most rural areas. So, yes, you had $400/year to spend, but what you had to spend it on was much more limited, and much less pleasant, than what we have today.

If I took my 1921 Morgans back to 1904 I would probably get arrested for forgery.

Steve

Can probably only look at this type of comparison on an example basis rather than a rule. For example, compare the cost of bread to bread at a specific place/time to another time as another poster mentioned. Even today, prices for the same things vary across the country. Another point to consider is standard of living. People tend to have a lot more possessions these days. A "poor" person today may have a more cushy lifestyle than a middle class person 100 years ago. The value of a silver dollar has eroded, but the value of what that dollar was made from can still buy something like a nice meal today (1 oz silver => $28 => nice meal). Would 1 dollar buy a nice meal at a restaurant back when those coins were made?