ehh there's 2 versions of this story...both of which seem very plausible.
One story (mainly supported by those who hate Rangers management) is that the Rangers pulled out of this deal because they thought that Mike Lowell was "done" and a throwaway piece of the deal, and didn't want to give up Blalock, Danks, and Arias for "just Beckett".
The other story (mainly supported by those who are more favorable towards Rangers management) is that Florida had no intention whatsoever of making a deal with Texas, and they just used Texas' interest to drive up the price. The Red Sox were initially unwilling to include Hanley Ramirez in the deal, but once they heard the Rangers were involved in talks, they decided to put him into the package and the deal was done.
I hate Tom Hicks and Rangers management, so I tend to believe the first story more.