On a recent trip to Sydney I visited the Reserve Bank of Australia's
Museum of Australian Currency Notes. From the displays comes the following interesting information about prices in "the 1900's":
6 shillings a week for meat
16 shillings a week for groceries
25 shillings a week for rent
£250 for a Model T Ford
House equal to 10 times annual earnings
During war years average weekly earnings were £3
Given that there are 20 shillings in a pound and a pound is equal to a sovereign, which is equal to 0.2354 ounces, we can convert those prices at say AUD 1400 ounce into today's money:
$99 a week for meat
$264 a week for groceries
$412 a week for rent
$82,500 for a Model T Ford
$514,800 for a house
Of course this is a bit imprecise given the prices are as at "1900's" and wages are as at "war years", but it is a reasonable holding of value and certainly more than if one had just held on to paper money for a hundred years. See also
this post on the same theme regarding the 1966 50c coin.