Am currently in the process of making a character and found myself in a bit of a conundrum; should I pay the cost to give the character an extra weapon skill so he could have a spare sword.

It's a bit of a power gaming question really.
The concept of the character is a hunter and will be armed with a bow, spear and of course a dagger.
But then comes the question if it's worth it to give him a short sword as a backup.
As far as I recall the game doesn't have any rules for weapon breakage (shields do on the other hand) so the only reason to carry an extra weapon besides your main is on the chance you loose it or is in a spot were you can't use your main weapon because it's too cumbersome.

Now you can only lose a weapon through the disarm called shot or through a story twist by the LM and it's only the story that decides if you are in a tight spot like a tunnel.
So the question is does those situations come up frequently enough to justify the extra points at character creation to give the character the points for a spare sword?

Tbh, it's all a matter of making the points fit the character concept...

(Will later, depending on the answers, show you a mock up of the character but for now I'm more interested in general answers..)

I think it's vision-depending.
What you see fit for your character is the right way. If I'm not wrong, only the orc's bent sword can disarm a character on a called shot, and it don't happen on a dayly basis. On the other hand, if he's a hunter, your character don't come every day in a tunnel to see what's ahead. So I come back to the firs sentence: if you see fit for him to have a short sword as a back-up weapon, spend the points, buy the skill, and come every now on with a motivation to fight with it rather than with your spear.
If it's just mechanic-depending, spend the points on something else.