A 325e, it will be an upgrade in sound, but not a big leap..more like a refinement. The RS2e is generally very well liked and will be a very big jump in sound quality...but the higher up the ladder you go in price, the more you run into diminishing returns, I'm not sure you'll find them to be 200% better in sound. Which brings me to the third option you didn't mention: mod the ones you have now. For example, I had a leather headband made at my local leather shop for $20, I bought some aluminum cups off another headfier and upgraded my headphones myself and saved a bunch of money. Grados are really easy to mod, one of the easiest headphones to work on actually. You could make yourself some awesome looking and sounding headphones for a lot less than the cost of new ones.