Can I add a print button to the document that will print the last two pages rather than the entire document?
Yes.
// form1.page1.printBtn::click - (JavaScript, client)
xfa.host.print(1, "2", "3", 0, 0, 0, 0, 0);
And would the button need to be on the 3rd page (top of the actual form) or the 4th page (end of form)?
The print button can go anywhere.
Steve