are subaru legacy b4 1999 any good its done 175000 kms, should i buy it is going cheap!?

Old and cheap it is far better than most. Did the seller have the timing belt changed at 100k? Have him prove it. Otherwise you really need to get it changed first thing. And while you're at it, put on all new belts, new water pump, all new hoses and have the coolant system flushed. That will cost you about $1,000 - $1,200. Make that cost part of dealing with seller for a lower price. If this thing is a standard transmission, it can easily run to 250,000 miles or more. The engine will never give up. The early 90s Subys can run to 500,000. My '92 has 240,000 and still runs 30 mpg at 80 mph on the freeway.