In short, yes, they are worth the price.
You're paying mostly for the fit and finish. They try to make sure the grain alignment of the haft is perfect and they come shaving sharp out of the box and carry a 25 year warranty.
Can you get a lot of lesser axes for the money? Yes, but then you have lesser axes.
Can you get a few vintage axe heads for the cost? Yes, and the steel will be just as good. But you will have to find a good haft, file it down to fit the head, de-oxidize the head and put your edge(s) on the head. So, what you save in money, you pay in time and effort. If you're one of those guys that likes tinkering with things, and likes to restore old axes, it's not a big deal, just chalk the time and effort up in the "hobby" category and have fun. If you don't really like it, then bill yourself for the time it'll take you to properly select a haft, hang the axe, and finish and sharpen the bit. Likely it'll cost more then the Gransfors.
The expense of the Gransfors is all in the fine details. Axes that cost less don't put as much attention into those details. Even recent Wetterlings have come with some major flaws. Now, if you look at Council Tool's website, you see they sell fairly low-cost, American made axes and hatchets. Then go down to the bottom of the page and click on their "Velvicut" axes. These get attention paid to a narrower heat treat tolerance, proper hanging of the head and a sharp edge. Price-wise, they are right up therre with the comparable sized Gransfors. Quality costs.