since he doesn't have as much experience with the "audiophile earphones" i think most that are recommended would not be appropriate. They are all fantastic earphones ofc (i own the gr07 be) but even the be version my friends listening to them thought they lacked bass, and they could really appreciate the fantastic extended treble and the excellent mids
all they said was that they sound like my dre tours but less bassy.
so i would point you to this link
http://theheadphonelist.com/earphone-buyers-guide/
its written by joker
if you are like the average consumers (which is what we're using as reference) you should probably look in the basshead or the warm and punchy section (those would probably have the QUANTITY of the bass you would be use to) as most consumer earphones are very very bassy, so most of the earphones listed above are fairly neutral/balenced (gr07 and the fischer dba) as listed in the link
if i had to recommend something(s)
velodyne vpulse- very very deep bass, relatively clear mids and nonfatiguing treble
jvc ha fxt90- for the more aggressive, fun sound, with actually strong bass, mids and treble (some find it a bit too aggressive, but i would imagine average consumers wouldn't find it harsh)
the shure se215- very smooth mids and punchy bass, treble is clear but rolled off pretty quickly but absolutely no fatigue, id like more treble extension ( but i prefer a very extended treble, which is fatiguing to many others) which is why i didn't up buying them (tried them so many times, sittign on the fence)
another one is the fxd80- amazingly punchy and deep bass, ridiculously clear mid range, but unnatural and recessed for my liking (more suited for electronic and less vocal based music, not that they sound bad, just not as good as my gr07 and re400 which is saying a lot) and a treble that is bright (a bit too bright for others) and well extended
if you want to start on something cheap first just see if you like the bassy sound (but not near the level of bass you'd probably use to)
the philips she3590- 13$- i had these for a long time and these punch way way above their weight, its ridiculous, clear mid range but recessed and an decently sparkly treble and of course a very deep bass no bloat