I am not seeing any difference in the sell values when I equipped this artifact

There are many, many players that use the Alloy Value artifact every day. Though if it's a common artifact the benefit isn't that noticeable compared to a legendary one.

^^ What percentage is your artifact?
If its low you might not see a big difference over other things like techs and CW rewards.

Also, check if the thing you're selling is actually alloys and not an ore or items ("items" is only the things created by crafters, so its more restrictive than most people would normally use the word item).

it is legendary, I was selling aluminum bars. It's now working after I had it equipped for a day. The only reason I can think of is does it have a cool-down timer before I can use it? there is no mention on the card

It should work right after you equip it

that is what I thought but it was not showing. I even tried selling one bar to check and it sold at the same price as the one unequiped

you prob sold too many that but price was higher than sell, and it worked in a different market

no, same market same test with aluminum bar each time

once I saw the price jump from 2.2 to 4 something I knew it finally activated but I am not sure why it didn't work when I first equipped it but after it was installed for a day it worked

Did you just create your Legendary AV? If so, it would have been inactive (available to put in a slot, but giving no bonus) for the 5 days of the upgrade.

no, I have had it for a couple weeks.