Hard question. Almost like asking cost of a standard brand new car? A PAS can come with one speaker. Or two speakers. Or four. It could have an 8 channel mixer, power amp, a sub, monitors, or have wired mics or wireless.
That said, a good quality peavey set could set you back ksh 250,000 to 300,000. Good midrange speakers are about ksh 30k a piece. You need four for a big crowd. Mixer 30k. Power amp 40k. If you opt for power mixer, about 50k. Risky, less options. But it eliminates cost of separate power amp and mixer. Sub/amp unit 50k. Wireless mic x4 20k. Speaker stands, cords, and other accessories 20k. 3-5kva generator 30k. Most people find need for laptop too.