I use McAfee, the price varies according to what offer is currently on- it seems to be £30 just now, but my renewal date is in November, and I'm sure my renewal was more than £30! When I worked in online fraud Kaspersky was regarding as being the best by our technical teams, but I'm not sure if that is still the case. It's £40 a year.
But we have it covering 2 laptops and a desk top as well, so it does even itself out.
Beth