With all of the free agents hitting the market this year (plus the inordinate amount of time we have been allotted to talk about them before they can be signed), the Jets have a lot of options of what they can do with their CBs and WRs.
They are unlikely to be able to afford to keep all of their free agents. Santonio Holmes will demand market value, while Edwards just wants a fair contract and to stay in NY. Cromartie is probably more in Edwards territory, wanting some stability to stay where he is as long as the contract is fair.
Both players were not well liked by their former teams and have taken a liking to the way things are run with the Jets. Holmes, however, comes from a top organization in the Pittsburgh Steelers, and things were probably going fairly well until they traded him. He probably has little idea that he happened to play for two of the most well-run teams in the NFL, and there are a lot of teams that are not so hospitable.
That said, here is my idea - live without Holmes, and keep Edwards, then go after Nnamdi. Nnamdi and Holmes will probably demand similar contracts, although Nnamdi may cost a tad more. this will give the Jets perhaps the best CB tandem in NFL history. Remember the days when Revis had to be on Wes Welker all the time cause Cromartie is too damn lanky to cover those little dudes? Yeah, Nnamdi can do that. He can also cover TE's. You can play Cover 0 all the time with Revis and Asomugha, which wil improve all facets of your defense.
While Holmes did win us a lot of games last year, the Jets would have never been in those situations had the defense played in its 2009 form. I would take a 3rd year Sanchez with his 2009 weapons (who did okay for the first four weeks without Holmes anyway) plus a ridiculous pass defense over Holmes any day.
Besides, Shotty gets confused when he has to get the ball to all of these receivers. Sometimes its best to keep things simple for Brian.