$6.50 a year is about the cost of an umbrella drink or two at sailaway. Hardly an outrageous price.
Frankly, if you can't afford $10 a year or less for gilt-edged worldwide travel documentation, you simply can't afford to travel. Oh, and be aware, if you ever go to places like Russia, China, Japan and some other countries (including many African countries), you have to get a visa put in your passport before you leave the US, and there is an additional fee for this, payable to the country you are visiting.
There are incidental costs associated with travel. A passport is one of them. Travel a lot, use it often, and keep the price per trip low.