Just for the record, you don't have to spend £80 – I ordered my Marathon Winters a couple of weeks ago via German site actionsports.de, and the cost was £54 delivered (and the Snow Studs are even cheaper). Whilst I fully appreciate that is still a lot of money, I ended up deciding (with help from the lovely folks here on CC) that it was worth investing so that I could continue to commute through the winter months, and I also expect to get a few years out them which reduces the financial impact somewhat. Plus with a 28.6 mile daily round trip, I'll continue to save money by not having to put diesel in the car
It's my first winter commuting, but the studded Marathon Winters have been a revelation – yes, ice still commands respect, but they have kept me upright when I'd definitely have been on my back-side had I risked taking the road bike, or stuck with my normal Conti Touring Plus tyres.