A safety or straight razor would probably be best for value over the long haul, and they are less wasteful, but I could end up looking like I went through windshield. Rite Aid has a knock off of the Gillette Fusion for about a third of the cost. I'm tempted to try it and see if its close to as good.
I came to mountain biking from motocross, and didn't own a road bike for the first five years of my cycling life. In the late '80s/early '90s most of the pros and about half of the Experts had shaved legs. I raced my first year as a sport and the idea of shaving my legs never even crossed my mind. In my second year, first as an expert, the idea crossed my mind, but I didn't shave them. The opening race of my third year was the muddiest race I did in 25 years of racing. My legs were caked with cold sludge, but the shaved leg guys were much cleaner. That's what did it for me, I shaved my legs the next week. In the years of living out of my pick up trying to be a pro dirt racer, shaved legs made post race clean up a little bit easier. Plus, as someone already said, it is part of the culture, 'how can you be a serious cyclist with hairy legs'? RE: Time: I spent maybe 10 minutes a week shaving my legs, and if I was busy I might go two weeks without shaving (travel, work, train, eat, sleep...).
Funny: A friend of mine had a room mate who shaved his legs one day. When asked why he shaved his legs, he said that he was thinking about buying a bike.
