I was just reading an old book review on a collection of published papyri (P.Mert. vol. 1) written in the middle of the last century and was surprised by what, in the mind of the reviewer, was considered back then to be such an expensive book that it was basically out of the price range even of specialists (in this case, papyrologists). The reviewer, Naphtali Lewis (1911-2005), said this in Classical Weekly, 44 (1951), 152-153, here 152:

Since its price places it beyond the reach of many or most of those who work with papyri, it is to be hoped that copies of this most useful publication will be found in all our large university libraries.

Now, this is a fairly common statement to find in a review on an over-priced volume, but what was the cost of the book? £12! After the initial shock, however, I quickly realized that the effects of inflation over the past half century should probably be taken into consideration. I did some research therefore and found out that £12 in 1950 was worth about $34, which today would be equivalent to about $283! So, I guess Lewis was right: while scholars today don’t normally make a huge amount of money (relative to other educated professionals anyway), the volume itself would certainly have been a bit out of my budget and probably that of most scholars. But that’s why we do book reviews, right Dr. Lewis?!