What does one do with one year's wages worth of Spikenard?

And while he was in Bethany in the house of Simon the leper,
as he sat at meat,
there came a woman having an
alabaster cruse of ointment of spikenard very costly;
and she brake the cruse,
and poured it over his head.
Mark 14:3 RV

The first time I read the above, It struck me as a completely surreal image. Jesus sitting at a table, his whole head and face covered with ointment. It reminded me of the story about Syd Barrett:

Barrett avenging a particularly severe Bad Hair Day by crushing a load of pills into a jar of Brylcreem and then pasting the mixture on to his head. When he stood under the stage lights, the mixture liquefied, giving the audience - who were doubtless as "zonked" as poor old Syd - the impression that his face was melting.
http://www.johnharris.me.uk/arch/interview/quaaludes.htm

I am not suggesting that Jesus was "zonked", nor the disciples, nor the woman (Mary in John). Neither was I when I read the story.

My reaction to reading it was one of confused amazement; the disciples who witness the anointing have no such issues: their concern is material.

But there were some that had indignation among themselves,
saying,
To what purpose hath this waste of the ointment been made?
For this ointment might have been sold for above three hundred pence,
and given to the poor.
And they murmured against her.
Mark 14:4-5 RV

We are told by Matthew, Mark and John that spikenard is valuable.
Both Mark and John tell us 300 Denarii worth.
Matthew elsewhere informs us:

And having agreed with the laborers for a denarius [for] the day [i.e., a normal day's wage],
he sent them into his vineyard.
Matthew 20:2 ALT

The spikenard was worth a years wages.

Why was it so valuable, and why did this woman pour it on Jesus' head?
In this time, spikenard was used to annoint to dead.
It was extremely aromatic:

and the house was filled with the odour of the ointment.
John 12:3 RV

Due to it's strength, it was used to keep a corpse from smelling.
As Jesus informs us,

For in that she poured this ointment upon my body,
she did it to prepare me for burial.
Matthew 26:12 RV

But in John, Jesus tells the disciples:

Suffer her to keep it against the day of my burying.
John 12:7 RV

In Matthew and Mark, the woman pours the ointment over Jesus head.
However, In John, Mary anoints his feet, then wipes them with her hair.
In Luke:

weeping,
she began to wet his feet with her tears,
and wiped them with the hair of her head,
and kissed his feet,
and anointed them with the ointment.
Luke 7:38 RV

This is a highly charged, intimate scene.
Interestingly, the only other incident within the Bible that spikenard occurs is overtly erotic:

While the king sat at his table,
my spikenard sent forth its fragrance.
My beloved is unto me as a bundle of myrrh,
that lieth betwixt my breasts.
Song of Solomon 1:12-13 RV

While I no longer see this event as surreal, I am aware that the full meaning of it may not be as simple as I thought.