I managed to get this whilst going for:
In Hendon Myre, there in an NPC called 'Sharan' who runs the Prestige Salon shop. You can buy Legacy sets from her which can pop you the achievement.
I bought the Sya set for my Fighter. The sets are as follows:
Light Armour Set:Legacy: Sya Chestplate of Meti
Legacy: Sya Gaiters of Meti
Cloth Set:Legacy: Cotton Coat of Meti
Legacy: Cotton Pants of Meti
Leather Set:Legacy: Leather Jacket of Meti
Legacy: Leather Pants of Meti
Heavy Armour Set:Legacy: Ring Hauberk of Meti
Legacy: Ring Gaiters of Meti
Each piece of equipment costs 5 life tokens each - meaning a total of 10 life tokens for the set, but have excellent stats on them and awesome set bonuses.
These sets CAN be obtained from breaking pots you loot in dungeons, but are obviously rare and could take a longer time to obtain.
edit: An important point I forgot to mention - you do actually have to equip the set for the achievement to unlock. Thank you,
Metamania2313 :)