warmer? puffys I suppose. But you get what you pay for. and if they are some of the cheapest pants in Oakley's line, they are made cheaply. Check out Burton pants, for the same price you can get 20,000 mm sick pants
Freezed and AnotherPE are right. If it is a sunny, dry day, 4 or 5K won't be that bad. But, if you ski a longer day where snow is constantly touching your pants (powder much?) you need 10K or better