Guild Wars 2

The first completion of the day in a particular Explorable Dungeon path yields 30 tokens.
A set of dungeon armour currently costs 1380 tokens.

Thus a minimum of 44 runs is required for a complete set of armour.
An efficient team who is traited and gear with a purpose can complete Arah in 1.5 hours.

Thus 66 hours is a lower bound for the time taken to obtain the armour set, with a minimum of 11 runs of a single path.

It is my firm belief that Anet intends to make the dungeons less of a grind.
There are many games where it would take upwards of 66 hours of repetitive activity to obtain an endgame item or item set.

This in no way detracts from the fact that currently, obtaining your dungeon armour is a grind of significant length no matter how you do it, and thus, running the first two bosses doesn’t cheapen much as there isn’t much of an experience to cheapen.

It is flagitious of those who have not obtained dungeon gear to comment on how one should do so. I very much hope and have confidence that they will be dynamic in time, but right now, everything is a farm.

My advice to those wishing to experience the game but also obtain their gear efficiently, try all of the explorable paths once. Then farm.