Personally, I think you're trying to ask too much for the means available to you. I can tell you that for the money ($91.xx- something on the main forum page right now.) that the AD700s are probably going to be difficult to beat for the budget. If you need bass, look into maybe trying to drive them with something better than you have right now. I think, even owning the AD700's that you're only going to compromise by trying to find exactly the same quality, with more bass. I think the 700's sound like they could be had for twice the price, trying to find that in a different phone, with more bass, may not be so feasible.
I'm a sophomore in college, and I've paid for every part of my rig by myself. If it's really important that you get beyond the offerings of the Audio-Technicas, I would consider looking into doing a lot more homework maybe before making a purchase, and reorchestrating your fiscal priorities to accommodate your audio needs. I went for a long time without buying alcohol, for instance, to get where I needed to be sonically. It's really about how much you're willing to sacrifice at this age.