I ran a homemade set last year and they worked fine. I used sheet metal screws and they do wear out. I ride about 100 miles a week and the back tire needed a new set of studs by mid-February. The front tire looks like it is still sharp, although I have a spare for the front that I swap out when the roads are clear so it got less use than the rear.
Takes about half an hour to replace them. I figure $5 worth of screws should last me 10 years.