It's been reported that the Mets will attempt to shake up the roster through the trade market. Whether we like it or not; it appears that ownership still isn't in a position to spend on free agents, while the front office acknowledges that changes need to be made.
The only way for a team that is broke to make significant changes to the roster is through trades and remember other teams aren't in the business of just giving players away because you want them. A fair trade while filling the needs of both teams is also painful for both teams. You don't get something for nothing unless they're damaged goods or not that significant a piece.
The Mets have been a below .500 team for three seasons, during which time many of their younger players have had a chance to develop, none of which have shined. Teams can argue Davis is too streaky, Duda lacks confidence and Murphy is a singles hitting DH. While some of the players on the major league roster might have appeal to other teams, they aren't going to garner big time returns.
Probably the two players on the major league roster with the most value are Ike Davis and Jon Niese both of which you probably want to build around instead of trading away.
Signing David Wright may kill two birds with one stone, not only does it lock up the face of the franchise for probably the rest of his career but it also may give you a very appealing trading chip. If Wright is locked up for the next six or more years then your top positional prospect is completely blocked.
The 21 y/o Wilmer Flores is the Mets top positional prospect and the #3 overall ranked Mets prospect. The problem is that Flores is a third baseman and the team is looking to extend Wright at that position for many years.
Flores has already out grown his natural position of short stop, after 450 minor league games at the position he hasn't played there since 2011 when he was 19 y/o. Many 3B move to 1B but the Mets have Ike Davis and/or Lucas Duda filling that position. There has been some speculation that he could move permanently to 2B where he has played 27 games for the first time this past season.
If the idea is to trade from a position of strength then while it's hard to give up such a young promising prospect he might garner the biggest bounty while not effecting the teams long term plans.