Maybe clarification of terms is in order. A "package system" usually has tuner, amplifier(s), speakers and disc player (maybe tape player) all in one box. At best it may have separate speakers. This type of system is almost always poor quality.

A used integrated amp (preamp and power amp in one unit) has little to go wrong and may last a lifetime (obviously we are talking solid state type, not tube). If a radio is included in the unit it is called a receiver.

A used, tested receiver made 20 or more years ago often sounds better than current models and costs about $50-75. Add the AR speakers you already own, and a $69 new Phillips DVD player (useable as CD-only, if you choose) and you are out approx $140. Think of all the CDs you can buy with th savings.