i think getting a mount is better for both.
with full green bc set, on lvl 4, you will usually use all ur elixirs to kill a vet deamon hound, which will make you lose tons of money, and you will get tons of exp, which will make you level to 5 really fast, and then you will be to weak at lvl 5.
you can go naked and hunt vet demon hounds, which usually get you profit if you buy food in exchange.
you will also barely get exp (just from auto-hits, usually u will die before the auto-hit), which will make u stay more time on lvl 4, and get you more tokens, to buy a purple set.
then when u will reach lvl 5 you will have a full purple lvl 5 set.
so you get a great set, and a mount that helped you save a lot of money.
from my experience though, best zorb/tiger to get is the level 5 one, without making him poison, cause u will have to pay lots of money on food, rest of the tiger/zorbs will be really weak compared to the level you will be at, and you will rarely use it, and the money you will spend to get them... bleh...