SOG's tomahawks use cheap steel, but are really good for the money if you are wanting one for throwing. Overall, they're pretty durable; the connection between the handle and the head is pretty strong. Good for fun, but bad for utility because of the blade steel.
Benchmade's tomahawk is a great all-around tomahawk with a good combination of quality/construction, and price. It's ergonomic and great for throwing, utility, etc.
Another great tomahawk is the American VTAC. It's priced reasonably, is made from good steel, and is pretty much indestructable.
One of the ultimate tactical tomahawks is the RMJ Tactical. It's a full tang tomahawk with G10 scale handles, great steel that's differentially heat-treated, and is actually used by our troops. It will cost you an arm and a leg though (literally, if you're not careful!)
Are you looking at getting a tomahawk? If so, what's your intended purpose? Tomahawks are not ideal tools at all for your average person/camper/hiker. Tomahawks excel when you put them in the hands of a soldier, where they can be used for combat, breaching, penetrating many tough surfaces, breaking glass, etc.
However, they aren't very good for your everyday person. They aren't ideal for camping; they're pretty much half way between a knife and a hatchet. Not best at cutting firewood, but also not very good for cutting things with precision. The average person also probably won't ever be in the situation where they will actually use a tactical tomahawk for combat. And you definitely shouldn't be buying one so you can break into buildings! :xeye:
Tomahawks are a great buy if you're looking for something fun to throw that you can also keep in your car for emergency situations such as car accidents. Some people might even find them to be useful for backpacking. I definitely don't reccomend shelling out $500 for the RMJ unless you are about to be deployed, but if you're just looking for a fun, multipurpose tool to have laying around, take a look at the Benchmade or the American.