You cannot open any Pages documents created by Pages v5 (Oct 2013) or later in the iWork '08 or '09 Suites because the internal document formats are entirely different. You might be able to open those newer Pages documents in Pages for iCloud and then download it as a Word or RTF document to Snow Leopard. I have nothing here to test that theory.
The oldest export feature in the current Pages applications is for Pages '09, and that may or may not open in Pages v3.0.3 in iWork '08. There is also no guarantee that if instead, you received a Word DOCX, or RTF exported from a current Pages application whether it would be entirely compatible with the iWork '08 suite. Experiment with that.
This is a classic case of time and technology obsoleting your choice of status quo.