in case you don't know how to send items, I'll post a pic taken from this guide by Flute.

lup essences are usually priced about the same as vul, so it doesn't matter to me.

if you want to trade for a lup essence, you may send me your vul essence without any CoD.
I hope you trust me enough to do that :D as soon as you send the essence, I will send mine.

if you decide that you want me to pay for it, send it with a CoD of 50k.

aaand the pics.