Here is a very interesting specialized collection of the 8c centennial. This was put together by long time dealer K.Bileski.

Here is what is in the lot, however there may be variations in the paper fluorescence etc. This price assumes everything was the cheapest variety. 

There are 22 covers in this lot: (note that the Bileski description references more but all of these lots have the 22 items pictured here)

544 single and block covers (2 FDCs total)

544a booklet pane

544qiv booklet pane

550 pair

550 two pairs theroretically imperf between but a score line is visible

544p winnipeg tagged single, block and matched set of plate blocks (6 FDCs total)

544pi ottawa tagged single, block and matched set of plate blocks (6 FDCs total)

4 pieces of postal stationery, a mint and FDC used copy of each

The Bileski marketing page (which references a larger number possible, this lot only has the 22 items pictured)

The pictures represent the first day covers in this lot. The pictures are of one of the lots, all of the lots have the same covers in them.

APS, CSDA, RPSC, & BNAPS member