Don't really know much about mountain bikes, but I'm kinda sorta in the market. Is this a good deal or no?
KONA KIKAPU FULL-SUSPENSION ALUMINUM MOUNTAIN BIKE, LARGE GOOD CONDITION 1x9 SRAM X-9 SHIFTER AND REAR DERAILLEUR SHIMANO CRANKSET RACE FACE CHAINRING HAYES STROKER TRAIL BRAKES HYDRAULIC DISC...
Not bad. If you do a lot of climbing, the rear suspension will probably bounce a lot and eat up a lot of efficiency. Pretty nice build kit for its time, which is probably mid-2000's. I personally really like bikes from that era and earlier. Only thing I see that might be problematic is the 1x9 drivetrain (1 front chainring and 9 rear chainrings/gears). Most of the newer 1x bikes have a smaller front chainring and a much larger rear cog (40-50 teeth), whereas that one looks to be in the neighborhood of 30 tooth front and 34 tooth rear. Basically what that means is your lowest gear isn't that low, around 1.1:1. When I was in good shape, I never used the small chainring up front, and rode everything around in the middle ring on the front (around 30 teeth) and the big ring on the rear (34 teeth on mine). But for long hills in the mountains or now that I'm fat and lazy, that wouldn't cut it. If you wanted to swap the rear cassette out to a bigger unit you'd need a shifter with different throw, and the derailleur likely doesn't have enough travel, which means you would have to replace the cassette, derailleur, and shifter (and that's only if the hub is wide enough to accept the new cassette and there are no clearance issues). My current bike (which I just listed for sale last night actually) is a 2x10 with a 24/38t front and 11-36t rear for gearing range of 1.5:1 in low and 1:3.5 in the highest gear.
TL: DR Take it for a test ride and see if you like it. It's an older bike that may be limited by suspension design and gearing, but if it works for you, it looks like a quality piece.
Here's mine, it's a size small, and probably comfortable for someone up to about 5'7". Log into Facebook