I finally hoarded all the requirements to craft a T5 amulet but for some reason I couldn't craft it at all .
The base price of T5 (Artifact) Amulet is : 4000 fragments - Since I had only 3609 frags at the time, I adjusted the % use of fragments in this attempt to 90. - it calculated that I needed 3600 fragments. - clicked on the Craft button - crafting failed with an error reporting that I didn't have enough fragments. - at the same time, I noticed that for some reason it subtracted 1831 fragments off my 3609 frags. - but when I refreshed the page, all my 3609 frags were back again