Best way to get a precursor in GW2

For now few weeks I decided to get a Legendary Weapon, all the recipes are pretty simple but yet quite expensive.

• T6 components are easy to find or at a reasonable price.

• Since the last Update (16/03/2015) WvW maps don't count for the map completion, So I have the Gift Of Exploration.

• Bloodstone shards costs 200 skill points, Obsidian shards are pretty hard to get but playing a bit PVP WvW every day and i got them.

• Other components are easily affordable.

The most important thing to get a Legendary weapon is to get a Precursor, and the only way to get one is using four weapons of the same weapon type guarantees receiving a weapon with that weapon type. For example, players can combine one level 60 rare weapon and three level 80 weapons. Player research into the chance of receiving a precursor when combining four exotic weapons of the same type estimates the probability at 0.79% with 2901 trials.

I have tried a lot, spending a lot of money but nothing.. So I was wondering if there was other ways to get a Precursor because I can't get one with the MF, and I can't save enough money to buy it in the BLTC.

So, are there other ways to get a Precursor?