What determines price to sell to store? (in General)

Hopefully a quick answer to the title?

Now we have NW on home I'm just a little bit curious about the fact that my 10 mill NW ToA sells to store for 1.75 mill and my (rented) Morg of 20 mill NW sells for only 0.75 mill to store......

the higher the NW the lower the 'rate' of selling it back to store is, also Tattoos seem to have a bit different rate than other items?

I also think (but not fully sure) the X is valued higher then the + on a weapon.

FAQ: Store.

"Q: What percentage of the actual "value" can I sell items back for?

A: The store will give you 80% of what it would sell the item for. If you've been upgrading at the blacksmith, this will be far less than you've paid for it; the blacksmith charges a hefty premium. Except for very low-level items, you'll probably get more of your money back by selling through Auctions."

That's the Morg sorted, but Tattoo's aren't Blacksmithed/Forged. Where's the premium come from?

;)

Ah, yes, I read the FAQ, but didn't notice the bit about the blacksmith - that explains a lot of the differences between sell to store price on my items.

There should be a big notice on your home page to remind you 'READ FAQ AND HELP PAGES PROPERLY BEFORE ASKING QUESTIONS' - but of course you know nobody here reads anything properly lol!

The value-additive aspects of growing with use & earned XP, which is effectively the same as growth by BS or forging.

(Pedant!)