The post office is offering a discount if you use their supplies for your mailing. The $7.70 rate is a flat rate for PRIORITY MAIL service using their supplies, a rectangular box about 12x14x3. All you can fit in the box, no matter the weight for $7.70. Its actually a great deal. Guess whoever was running the tape machine didn't reset it, or didn't bother to look for other methods of shipping, first class or media mail. I've learned by experience that you have to check out things. For example, media mail (music, books, printed matter) rate is cheaper, a single audio CD on media mail is about $1.27, but only .60 for first class.