Yes, you pay a premium to get a new thing.
But there are a couple of real advantages in buying new - for bicycles, the two big ones I can think of are warranty (bike company warranties are not tranferrable from the original owners) and size selection (there are lots of used bikes on the market but not too many in my size).
The other thing about 'used' is that you are always guessing about the condition - even if it looks clean, that doesn't mean the hub bearings aren't worn out or the frame hasn't fatigued.
I have only ever bought used cars. Four years ago I bought a Mazda with ~60000 km on it. It needs ~$1000 worth of suspension repairs now.. The same time I bought my car, a friend bought a new Toyota. The only repair he has needed is a brake pad replacement. I know he paid more, but I feel the peace of mind he got for the extra money was worth it.