I'll put my librarian's hat on to answer this.
By all means put the price on the book, but indicate the currency (USD). Those of us in other countries will realise that we pay a different rate and will compensate for it.

Put some contact details as a help to people who come across the book in the future and want to order it - even if they change in the future if it is current at the time it gives them a starting point to trace you. I assume you are self-publishing? Otherwise the publisher's details would be sufficient for people to order. Make sure the author's name and the title are clear - and the date and place of publication. These details are usually on the title page and again on the verso (back of the title page)with copyright details. Include an ISBN. Hope this helps