There's a sticky thread in this forum about making your own, to -
http://www.bikeforums.net/showthread...-Studded-Tyres
According to Sixty-Fiver, the studs only contact the pavement when you're about to slip and this works well. I cannot say.
I will say that the major disadvantages of making your own are usually that -
1. Homemade studded tires where the studs contact the ground regularly, like if your route is 75% plowed pavement and 25% snow and ice, wear out much faster. Nokians and Schwalbes use not only "hardeded" steel, but carbide - a material so strong the tire casing nearly always wears out before the studs do. If they do wear, one day they'll work, then one day they just won't work any more. This has also been a problem with the cheaper studded tires from Innova that use cheaper steel in their studs.
2. Again if the studs contact the road regularly while rotating, home made studded tires are much, much slower than the commercial ones.
3. You get what you pay for, and a $10 might not be the best thing to ride, studs or no studs. Flats, early wear, etc. No puncture protection.
4. If you don't do it right, the screws can puncture the tube on the inside of the tire.
My summer tires cost at least $30/tire (cheapest decent, flat-resistant tire I know of). Peter white sells the Nokian 106's for $45/tire. If you figure screws will cost a little bit, and that the Nokians will last a lot longer than my home made tires, the Nokians are actually a better deal financially for me.
The most popular use for home made studded tires is offroad riding, where the studs don't wear much because they don't come into contact with the pavement.