I was at the office max this morning and the woman in line in front of me had packs of photo paper - a pack of 8 1/2 x 11 and 2 packs of 5x7. Nosy person that I am, I said to her "excuse me for being nosy" (I always start with that, people tend to be more receptive if you start by apologizing - LOL)..."but did you know that its cheaper to just buy just a pack of 8 1/2 x11 size paper? If you cut it down right, you can get 2 5x7 photos from each 8 1/2 x 11 sheet".
She looked at me for a minute and I thought she was going to tell me to buzz of....but she said "Oh my god, I NEVER thought of that! It makes so much sense. Thanks so much!" and she ditched the packs of 5x7 and saved herself $30.
So, the moral of the story, in case you havent figured it out, or already thought of it yourself - there is never a need to buy 5x7 paper - get yourself the 8 1/2 x 11 and cut it down. Its cheaper and you get twice as many photos from it. Even if you have one of the small photo printers that only takes the 4x6 and 5x7 size, its still cheaper to buy the 8 1/2 by 11 paper and trim it down to fit your printer.
(there is a trick to cutting it though - you have to cut it to 7 inches first by laying it the "wide" way and making it 11x7 , then you cut your two 5x7 pieces)