Today I went to the local Staples store. Among the things I needed were some CD storage sleeves (the square envelopes with round plastic windows in front).
There were several offerings. My choice narrowed between a box of 50 plain white sleeves and an otherwise identical, same-brand box of 100 sleeves.
Price of a box of 50: $6.99. Price of a box of 100: $14.99.
I'm not making this up. Honest Injun.