If you're looking for excellent singletrack and plenty of xc riding you might want to consider Revelstoke, B.C. and it's close enough to Golden for those days when you'd rather do the serious dh riding. Unfortunately, the only dh skiing in the area is Golden but I think the xc skiing would be okay. Revy is known more for the helicopter skiing. Granted Revy isn't a party town but it's cheap to live there.

Another option is Nelson, B.C. There's lots of excellent xc and dh riding in the summer and Whitewater is the local ski hill. Their average base is 250 - 320 cm of snow throughout the ski season so they get a fair amount of snow.

You might also want to consider Rossland, B.C. Another mecca for both mountain biking and skiing. Rossland and Nelson are within an hour of each other and there is a vast rural area inbetween both towns where the cost of living is cheap.

Of course, the only drawback (and one can usually find a way around this in this area) is the drinking age in BC is 19.