[sushibowl]

From what the bros here say ( i haven't heard the RE0s before) you are not going to find something with the clairty the RE0 with more bass without having to fork out much more.
 
I think some EQing might be in order. Or go for other earphones with more bass presence like the NE6/7, Eternas (might be too much though) or the Meelec M11+.
 
IMO your best choice is to buy a bass amp and do some EQing. You save quite a bit plus you get the use the amp on other earphones in the future

 

[Currawong]

Here's a question for this bumped thread from last year: What if I have RE-ZEROs and want the same thing, BUT, I own a Pico Slim already? EQ'ing is out of the question, as my iPod Classic has a screwed EQ. RE-252s? Or something else?