Only you can determine if they are "worth the price" base on your own personal values.
But the prices seem to parallel the sum of the cost of a Mag light, and the cost of the LED module if one shops carefully, and overall, the cost of the assembled light with the LED module is generally a bit less than what you would pay for the combination of the two separately at the same store.
You might want to take a look at some of the threads that are already on this forum to get an idea of user's impressions. No one has run any kind of 'scientific' run time tests, but the consensus seems to be around 30 hours with D sized alkalines.