I don't really get what veteran players really want with sub offers. Personnaly the only thing i look at is the €/month ratio and the "free" months linked to it. The rest is bonus and usually i couldn't care less. Like some others mentionned, bank space could be nice but i can live without.
What i'd like would be to be able to chose some awesome vanity set and translate my PvP set stats on it so i'd look good even in mini-games ! Got to look good to gank with style
But that's probably too much to ask