Right now I don't feel like wasting money cursing dummies or anything like that so I was wondering if anything is profitable to mage (combat) at my level. My level is 51.

Blue dragons. Use Chaos guantlets and fire bolt

With 51 mage he won't often on blue dragons.

 

Fire strike cows, or you could bolt desert goats (preferably with chaos gauntlets) for their goat horn, worth 769 unground 839 ground. They have 21 hp. Banking would be a pain, and the xp terrible. Just curse dummies.

These.. Dummie.. That you speak of.. You can Auto cast the things and walk away come back 2 hours its still going??

They don't attack you back (being dummies and all) so no, you would get logged off after 5 minutes.

I thought it was as long as you stayed active..

Try striking or bolting banshees. The XP won't be great, but you'll make money on the herbs and pure ess. And get an OK amount of charms, though they'll mostly be green.

Chaos druids would be worth a try, they drop a lot of herbs and are pro magic so you'll get a far bit of exp per kill.

Banshees beat chaos druids in every possible way - XP rate, cash made, amount of competition, and (I'm guessing, since it's a slayer monster) charm drops.

I've never tried maging either, but it was just a thought.