I am not talking about that cheap stuff. If you had gotten about 2/3 of the way into Nightfall, there are much higher and better armor sets to buy. The stuff in the docks was nothing more then a bit better then your good Prophecies armor. I solo'd with my Fire Elementalist almost all the way through Nightfall on my own.
Armor has a cap at certain protection for each class (Elementalist is 60). You can get a basic set of max armor for (about) 5k plus materials. Prestige/Elite armor, like Primeval, Vabbian, and Ancient, was just there for aesthetics and too show you're a rich bastard.
For example, http://wiki.guildwars.com/wiki/Warrior_Elite_Luxon_armorarmor has the same protection as the regular http://wiki.guildwars.com/wiki/Warrior_Luxon_armor, despite being the Elite version and costing 70k more.
And http://wiki.guildwars.com/wiki/Vatundothe Consulate Docks armorer, who sells max armor.