In another thread the idea of using the older Provincial stamps for mailing today within Canada was raised.
Here is a cover I received in December 2008:

The postage includes:
* 2 x 1c Macdonald (Canada 586as) [boring]
* 2 x 13c Charlottetown (Canada 224)
* 3c Queen Elizabeth (Newfoundland 255)
* 4c Queen Victoria (Prince Edward Island 14)
* 6c Queen Victoria (Prince Edward Island 15)
* 12c Queen Victoria (Prince Edward Island 16)
The PEI stamps catalogue prices are
more for used than mint. Of course, that would be "used in period", not 136 years later!