Price on 19% quality EK

So i got one and i know these are pretty valuable, but i have no clue about how much exactly. I have been offered 4 GCP but i refused since leveling a skill to such level would need way more than 4 gcp.

Is this the right line of thought? How much do you think its worth it?

Is no one interested in buying this or at least telling me how much it costs?

4-5GCP may have been about right.
I will trade my level 15 EK that has 15% quality + 1 single GCP if you are interested. Normally anything 15+ is priced the same anyways.
ign: packets

I'll give you 4 GCP for it.

would be worth 6-7 gcp to the right person, but it make take you a while to find them.