How to value unid items

Hi all,

I've had an unid item lying around in a WTS offer for a while and then got the question "what do you want for it?" and I had to admit to myself that I don't really know how to price unid items.
Is there a rule of thumb for that? E.g. assume it's a 75% roll and look for historic prices on that?
In my case of an

Eth HoZ, the extreme ranges I saw were a bad roll getting sold for a

Pul and a perfect one once fetched 20

Jah.

Thanks for any advice

I use the trade history of Traderie to check for already sold unid unique items. But in my experience only potentially high value items are worth selling unid (e. g. I sold several

Crown of Ages for 2

Jah and a pair of

Steelrend for 4

Lo. A few

Eschuta's Temper or a

Tomb Reaver I sold for a

Vex)

Look at 80% score price. Usually around that.
Or the other way, look at top 5% price x 0.1. pick bigger one
either way, makes seller long run win

for constantly sell and long run, lower than formula price is needed. (weekly sell)
or higher price for monthly sell...