I got 2 mage amulets today and was thinking about the mage quests, are they worth it or is it better to sell the amulets?

The amulets go for ~370K, the tomes (which you get from the amulets) go for around 3M. That said, the conversion rate for amulets to tomes, is around 1 in 7, maybe 1 in 10, depending on your luck.

So selling 7 amulets gets you 2.5M, selling 10 would get you 3.7M.

There are other considerations. The time it takes to submit the amulets, the luck factor - the more amulets you submit the closer you will get the 1 in 7 figure. There are 2 achievements to get related to the mage (do a single mage quest and get a tome as a reward), but once you've done each one time, that's no longer a consideration. There's also the issue of what sells better/faster - amulets will sell sooner than a tome, but I'm not sure 7-10 amulets will sell faster than 1 tome.

I use the tomes, so for me I don't sell either and its way better to get "free" tomes from the mage than buy them from other users.

Thanks for the information and advice!

Anytime!

Both options are profitable, but having the information lets you make the best choice for your style of play.