It's probably not necessary until you get to 4th job as Mercedes is a bit overpowered with that built in EXP bonus. You just need basic equipment and healing items. It's probably one of the faster classes I've played.
Depends what kind of gear you are aiming for. cRA bowmen is pretty cheap. You could probably get the full set for mercs for under 1b.
And I wouldn't buy a raccoon mask. I would go with sweet-h2o for the higher potential %. Plus you can scroll sw for att too. Got mine to 20.