I was going to send a regular-sized letter to my mom (out of the country,) and since I haven't mailed a "real" letter for a long time, I figured I'd check the USPS web site first for its rate. It's 94 cents right now... I don't remember exactly how long it has been, but last time I mailed an international letter it cost me 80 cents.
I started working at the post office at the University when I started college. Back then a regular letter / first class mail was 32 cents, and not too long after the postage was increased to 33 cents... It seemed so long-time-ago!
Back then I was sending a lot of letters and handmade cards to my friends, too! Ahhh... it was so much fun.
I believe the international regular letter would cost 60 cents to mail at that time... and then it went up to 80 cents not too long after. (I think... it's been so long!)
With that being said, USPS is changing the mailing prices again on May 11th this year. A domestic first class letter (under 1 ounce) will be 44 cents, and an international letter (under 1 ounce) will be 98 cents. We've got to have some of the penny stamps ready!