From my experience i can assure it all depends on the kind of server you are playing in and if you have money/tc to afford your gameplay, absolutely nothing else.
see simple facts:
Mages will ALWAYS thrive better than any other vocation since their aoe and consistent damage is a great point even in low lvls, something that a paladin can't obtain and a knight won't take approach of it up until great skills.
Paladin are the vocation that can afford the better their hunts, lets say if you were in a new server a paladin can simply hit lvl 100 without spending almost nothing and with lame skills (50-75) a mage in that case will need to resort to the usage of potions if u can't afford them from store/cask you are doomed, the best you can do were doing runes to afford tc, but in overall you are REALLY in bad spot.
Finally knights, this vocation at low lvl is simply lame, it require decent skill to hunt anywhere otherwise you are really below any other vocation in terms of exp/hr and profit/hr, if we talk about a new server this vocation can't afford their hunts properly until they have decent skills (65+) but is the easiest to play, even easier than paladin they have only 1 drawback and is that they only can kill 1-2 enemies at a time, while paladin must keep running with high chances to lure and mages MUST kill in aoe to obtain decent exp/hr.
With all that said, if we assume you are talking about a new server with no TC to afford your hunt, paladin have higher chances to thrive but you must learn how to hunt otherwise you will have a horrible performance and a knight were better for you, mages are out of discussion don't play them.
If we talk about an old server I assure you, as long as you hunt in imbuement hunts you will always have money so play a mage, it will thrive faster than any other vocation even if you hunt with target, then they become the vocation that do the most exp/hr in every place, just learn which places are okay to afford your really expensive hunt and there ends, you won't do huge profit in low lvl hunts, but you will hit lvl 100-150 faster than a paladin with 0 waste to profit then later you could start affording your own wands to increase your ml and better set instead of suffering to hit lvl 150 with lame profit, lame skills and really expensive aoe hunts.