UO Second Age

1) In t2a were you able to join the Mages NPC Guild to obtain cheaper reagents?
2) Is there a place hidden in a mountain south of trinsic that sells cheap reagents?
3) What's the fastest way to mine? Is it through mining out at sea, runebook mining or any other way I don't know?

1) Yes, you could have found that out by trying to join.
2) Yes, it's called hidden valley, although "cheap", no, it's normal prices.
3) There is no "faster" mining, no matter how you do it you still need the same shovel, and the same process of mining. You still need to collect the ore, and smelt it.