Pick up any Items in the Yabon-Lamut area.
Make sure you don't run into the relevant Enemies (if you do, it's no big deal).

The Caches available include:

The Chest SE of Haseth's Body
The Locked Chest near Squire Phillip
The SPIDER Chest
The DIE Chest
A House in Yabon
The LaMut Bridge

You will now have some more money, and plenty of stuff to sell. Go to the LaMut Shop, and sell all the extra Swords and Armor, until you have at least 55 Gold Sovereigns. (Don't hesitate to sell the Characters' Armor, if you need to.)

Now buy Tsurani Quarrels (price 55.0).

Exit the Shop, and use the LaMut Bridge Cache to multiply the Quarrels, until you have enough to sell for at least 192.5 Gold Sovereigns. (10 times should do it!)

Re-enter the Shop, and sell all the Tsurani Quarrels.
Buy Elven Quarrels (price 192.5).

Using the Bridge Cache, multiply these until you have enough. (Remember you need 2437.5 to buy the Swords and Armor.) You will probably have to do this 36 times, so be patient!

Finally, go back to Yabon and buy! That was easy, wasn't it? Slightly boring, as well, I admit.