Good Cartridge For an Audio Note TT-1

I have an Audio Note TT-1 with an Audio Note IQ1 cartridge, Michell Tecnoarm, Avid Pellar phono stage and Rogue Audio Cronus Magnum. I mostly like the sound -- detailed, dynamic, punchy, nice pace and rhythm -- but it could be a bit more full, slightly warmer and bass could be deeper. Any recommendations on cartridges <$500?
If you like the sound, I think the natural progression would be the IQ2 or 3 if you could find one used to keep it <$500. When I owned the TT2 I first auditioned the IQ1 and 2 and ended up with the 3. Each step gives you what you are looking for in fullness. The bass is going to be tough with the TT1 or 2 and something you're giving up to get liveliness of the table.
Ah, good feedback, thanks. I was thinking of picking up the IQ2 stylus next time I'm in London if it's much cheaper, but I was concerned about it not being a big step up from the IQ1. Is there a dramatic difference? (If I found an IQ3 for <500 in good shape, I may go for it but I'm concerned about buying a used stylus.)

But generally you think it's down to the TT-1 not being great at lower frequencies?
If you're looking for bass I don't believe you'll find it in the TT1. I listened to the IQ2 more than the 1 and found a big improvement from the 2 to the 3. I think if you went from the 1 to the 3 you'd be VERY happy with the improvements.