I have had this done on some tires in the past on my Paseo. This is a good suggestion, budget-wise. When it was time to replace the tires, there was no unusual tread wear from it.If you are on a budget and planning on upgrading later, find a tire shop that will heavily sipe your stock tires. While it will do nothing for compounding, it will give you a little extra grip in the snow/ice. Otherwise, only a snow tire will give you the best winter traction...even a cheap one is better than an expensive all-season.
I run the discoverer M+S with studs in the winter, i have mine in 245/70R16 as that was the size of my last truck, and they seem to work well, although they look small on the xterra.i'm living in Canada and working in far north so dedicated winter tires here is a must.
I would suggest : Copper discoverer M+S, Nokian Hakkapeliitta 7, or Bridgestone Blizzak DM-V1 of course studded