Currently the Asp is way out of my price range. Doesn't help i just got many self blown up in my CMkIII. The darn bounty kept ramming me! So that's nearly 300k down the pan.Diamondback Explorer and Asp Explorer (cobra was a mistype) are both widely available. Diamondback has the better range, Asp has the better internals.
RES? Had to look that up.Costwise yes, but you can spend one night in a RES in your Cobra and easily afford a DBX (and you can interchange a lot of modules between the DBX and the Cobra). The DBX will nearly double your jump range.
Despite the loss I mentioned above, I can already afford a DBX, but I've been unsure whether I want to get one. I guess I'll buy one & try it out. I need 10 ships anyway for a trophy. O