hi, actually it depends on the way u spend ur money. $4000 USD is abt $6000 SGD, if comparison between occupations can help u grasp the relative pay sense in SG, a fresh grad earns about $2800 SGD, a cop earns abt $3000. a teacher earns abt $3000.
u r flying with a budget airline so dun expect much like the national carrier of SG , SIA. Hope this helped.