Starting Monday, INS (renamed USCIS) will raise all fees:
new fee schedule. Now it will cost $675 to apply for naturalization (US citizenship).
Here is how it changes over time: it was set at $60 in 1989. It was raised to $90 in 1991, $95 in 1994, $225 in 1999, $260 in 2002, $320 in 2003, $330 in 2005, $400 in 2006, and now $675.
In 1999, when I learned of impending fee increase I rushed to apply just before the deadline. I collected all the documents, put a check for $95 and mailed everything to INS on the last day (it had to be postmarked before the fee increase). Two months later it all came back for unpaid fee: in all the hurry I wrote the check to IRS instead of INS.