How should one go about adjusting for inflation?

I found myself asking this in "Subsidy for the UK rail industry"

Usually, the answer is simple. Take the price, take the GDP deflator for the time, multiply and, hey presto, you have the price in today's money.

But there's a problem. As a blogger I want my posts to stand the test of time. I want them to still be read in 2024, 2044 and even 2104. But by then (assuming inflation continues to chunter away) 2004 prices will seem pretty meaningless.

So, rather than adjust prices to today's date, wouldn't it be more sensible to adjust them to some date in the past? That way you only have to make the adjustment once. So, rather than express everything in today's money, I could express it in 2003 money or 1803 money.

But if so, what date? Two dates spring to mind. The first is the year 2000. Nice round number. Reasonably recent. The second is 1900. This has the advantage of being at a distance from the inflations of today that are, incidentally, still going on. It also means that prices can be expressed in good old pounds, shillings and pence which would be a good way of preparing people for currency restoration.

The only problem is that it seems a bit weird. But if I take the lead and enough people follow suit, maybe, just maybe …

Actually, there is another problem. Knowing what prices were is not much use unless you also know how much people earned.