I own the Shure E2c and have heard them against the E3c. The E2c has better bass extension while keeping the same great midrange and highs. The fit and style are completely different, though, and will depend on your ears. It appears to me the E3c and E4c were designed specifically with the iPod crowd in mind, while the E2c and E5c are carryovers from Shure's line for working musicians. The E4c and E5c are both supposed to be terrific, but were way out of my, and your price range.
I've also heard the Ety 6 and liked my Shures better. The Ety 4 is supposed to be great but again, out of our price range. If you're looking for a bargain, I'd recommend the Sony EX-71. I thought it was virtually identical in sound to the E3c, and can be had for less than $50 online.
I've also heard the Ety 6 and liked my Shures better. The Ety 4 is supposed to be great but again, out of our price range. If you're looking for a bargain, I'd recommend the Sony EX-71. I thought it was virtually identical in sound to the E3c, and can be had for less than $50 online.