I can't help as far as the postage rates, but I personally love Prestophoto.com
They have an 8.5x8.5 size that I love. I think it's perfect, I'd printed 8x8 and 12x12 before, and I feel like the 8x8 is too small at the 12x12 is way too big. I've done over 40 albums with presto photo I've been print with them since 2009.
I scrap 12x12 and resize.
Here's an old article I did about the way I organize to scrap, but you can see the different sizes of my albums lined up in my cabinet. If you want to see an 8.5x8.5 in comparison to the other sizes.
https://www.sweetshoppedesigns.com/i...be-sunday-712/