Apparently the Mariners literally outbid themselves for Cano. Via Evan Grant of Dallas Morning News (and Michael Young MVP fame):
"By mid-day Friday, Seattle had heard that some team bid nine years and $225 million for Robinson Cano, so the Mariners upped their bid to $240 million and 10 years before apparently realizing the initial bid had come from themselves, too."
http://www.dallasnews.com/sports/texas-rangers/headlines/20131206-grant-with-all-of-mlb-going-crazy-on-friday-texas-rangers-took-care-of-mundane-chore-remain-lurking.ece