Yes, your York, PA cancel has an "E" rating which indicates that the cancel is "very scarce" and is valued from $10 to $20.00.
In 1991 Reg Morris and Robert J. Payne authored a 73 page study entitled:
American Service Markings
The Machine Cancel Society Specialized Study No. 10
The Service Markings attributed to the American Postal Machine Co. 1890 - 1918
Your cancel is listed as AMS-27. There were 2 different dials used. One was larger then the other - yours appears to be the larger variety. Booth have the same value. The dates of use are as Russ stated. The book is still available from the Machine Cancel Society. A google search will lead you to the Society.
As for value I think that
ebay has brought many covers on to the market and may have actually lowered prices. Since I aggressively collect AMS Service markings I would pay $15.00 if I did not already have several examples.
Good luck with your work in Guatemala.
Bert