hi everyone. So I'm currently level 7 and am taking my time on the main quest by regularly switching from side quests to dungeon diving to guild quests and then to the main quest. I had just finish the quest SPOILER ALERT spies and then martin said to get him a daedra artifact. lately Ive been hitting memorial cave for vampire dust and loot. So i'm wondering if the main quest has some opportunities to make some profit also if anyone could suggest a better dungeon for me to loot and level up since i'm only making 1-2 thousand a trip.

http://uesp.net/wiki/Oblivion:Rockmilk_Cave

edit: Yes, you can make a profit during the main quest. Loot everything valuable that your pack will physically allow you to, then sell it. It's the same as usual.

If you mean expensive artifacts you get as rewards, then I can't help you there. I can't remember any specific loot tables.