What fee
The last time I flew I was pre check and I have not paid a penny...
There are several ways to get into a pre-check line. These are the ones I know of:
1) have "elite" status on an airline that has made a deal with TSA -- this is currently being reduced though
2) have a "known traveler number" and enter it when you purchase your ticket (you get a ktn by enrolling in Global Entry, Nexxus, Sentri, or pre-check programs; or by being a DoD employee)
3) get randomly selected by a screener at the airport
Last year, when I was traveling a lot for business and was usually alone, I got routed into the pre-check lane many times via method 3. I definitely liked it better than being irradiated and groped, but wasn't willing to pay for it.
Then I got a new credit card where one of the perks is reimbursement of the Global Entry sign-up fee. Since that made it free, DH and I both signed up and now we get pre-check on every flight.
It's a sad waste of taxpayer time and money though, that DHS, who issued my currently active government security clearance, doesn't share their data with Customs, which is part of the same organization and are the ones who issue the Global Entry cards. They already had my fingerprints and answers to all the questions they asked me in the Global Entry interview, plus a whole lot more.