Salary cap is overrated. Maybe in Charlotte or Atlanta it would be a huge issue but in NY, the franchise that generates more money than any team in the league, it's not as big of a problem as some would lead you to believe. All going over the cap means is that a team will have to pay very high luxury tax. The Dolans are made of money so it doesn't matter. I hear they still own slaves. (joke) The Knicks are one big game to them. Could the franchise be ran better, absolutely, but what's 80 or 90 million when you're a billionaire and you make that money back with interest? It's not like they are losing money.
Why we really should get under the cap or at least acquire more marketable/tradable players is for D. Wade or Labron James. Knicks aint getting any where near under the cap for another two years. Trading Randolph would definitely be a step in the right financial direction.
Side note: Linas Kleiza is a quiet beast. I'd trade David Lee for him!