you'd actually be surprised how much some hifi's can take.. i've had to run vocals (screamed), keyboards and 1 guitar into a hifi before at HIGH volumes, playing with a drumkit and a large guitar amp in a (small-ish)room before.
was fully expecting it to blow up at some point but it held and is still going strong today.
get something cheap from cashies or sungei road, but yeah with a grand to spend you might as well get amps, or even a small PA system.