I will reccommend you to install pc based system. Cuz i think it is more flexible and economic than good stand alone system.
4Ch real time DVR Card prices around 250 usd.
Also i guess u wanna use the system at night and day. U can use IR led ccd cameras but these cameras have small life period relativly ( around 5000 hours ) .. I recommend you to use any ultra low camera ( 0.1 lux camera is enough.) with a little light source. it will solve your problem.
but if u have to use standalone system u cant find anything with 1500 dolars.
