It snowed here today, so I feel qualified to jump in. Last year I got a "cheap" set of steel studded tires, they were priceless on ice, but quickly wore down. Another co-worker, who inspired me to ride in the winter, has 4 years+ on some carbide tipped studs- they look new, after 100's of miles. The studs only help on ice, so if you're in an area that stays cold and icy, go for it, I'd recommend carbide tipped, such as Nokian Extreme. They're noisy and slow, but who is on their CF bike looking to hit a new speed record when it's 20 degrees?