I'd hate to have a large family who has never traveled and suddenly deciding to go to Europe. Granted that the cost isn't bad when spread over 10 years, but if you have 3 or 4 kids you are into some serious initial expenditures if everyone needs a new passport. But then, isn't trying to rationalize the cost by breaking it down to an annual thing flawed logic? You send in the application, new photo, etc., and a clerk reviews it and makes your passport. They then don't hear from you for another 10 years in most cases. What justifies charging $110? I think the fee should be more in line with renewing a drivers license...$25 dollars.
I also think you shouldn't lose time if you renew early. If I renew 6 months early my new passport should be good for 10 years and 6 months.