[bobcow120]

This is just a question about which would be the best value.
 
$232 for Vmoda m100
$155 for DT990 pro + $86 for E7
$129 for HD558 + save the rest
 
Also which one of these options would complement the M80's the best.

 

[squallkiercosa]

The best value will be the monoprice 8323 for 23$
 
Keep in mind, all headphones are commodities so even cheap headphones can actually deliver a satisfactory feeling. It really depends of your needs, the M100 are closed in comparison with the DT990 and the HD558, one is bassheavy the others don´t, where are you planning to listen? What kind of music... etc.