score:5
This is probably far too late to be of use to you, but may help others in the future.
To expand on another answer, many US telephone directories did indeed have lists of long-distance charges from their local network. For example, this extract is from the May 1920 edition of the New York City (including all boroughs) Telephone Directory:
with the following caveats:
On calls from stations located in the Borough of Brooklyn to Long Distance points listed below the initial Station-to-Station day toll rates are $.05 more than the rates shown.
For rates on calls from stations located in the Boroughs of Queens and Richmond to Long Distance points call "Long Distance."
As you can see:
A search of archive.org currently (April 2019) returns 90 telephone directories with dates between 1920 and 1930, inclusive. In this case
and choose the particular directory you are interested in. Most directories are available for download as pdf files.
Upvote:1
Old phone books from that era quite often had price schedules within, especially larger cities. Check a local large city library
Upvote:3
In 1915 (celebrating anniversary of the first call) Watson and Bell made a cross-country phone call and it was 20 bucks for 3 minutes. This would easily be the equivalent of 400 bucks today, arguably more. Of course, such calls went like this: You would contact your local operator, they would set it up from local phone network to the one in the next city, literally making physical connections so multiple operators would be involved and they would contact you when it was all set up. Without modern technology, the labor would make such a call probably cost 100s per minute. That we can call China for pennies a minute is amazing. https://www.cnet.com/news/at-t-makes-the-call-100-years-ago/