Initially I hated IEMs, however now I am used to them. If the isolation isn't a problem, then getting an IEM rather than traditional earbuds is a good idea. I still use traditional earbuds and keep the volume low then I am walking through traffic, but at other times, especially when I am sitting I use an IEM.
If you want traditional earbuds that are cheap, the Sony MDR-E828 is the first one that comes to mind. For around $8 it has plenty of bass. At higher volumes some distortion is audible, but at lower volumes it isn't really an issue. Of course this isn't as good as the Sennheiser MX580, althought the MX580 is now around 4x the price.
If you do decide to get some IEMs(and perhaps also the Sony E828) some good IEMs under $25 are the Panasonic RP-HJE355($19) which has great clarity and detail, the Panasonic RP-HJE450($24) which has more bass impact than the HJE355 but not as much clarity, the JVC Riptidz($8) nice balance sound, sweat and water resistant, and the Panasonic RP-HJE140($8), which has decent bass but not as much as the HJE450, and also less detail than the HJE450.