I guess the answer is no, it doesn't usually justify the added cost, otherwise people would have done it. If you need a heavier hammer, just make it bigger.
The advantage of tungsten is not so much weight, but density. You can make very small, heavy things out of it. I guess that's an advantage for bucking bars, but not so much for hammers.
Would people need a small but very heavy hammer? If so, then tungsten might have a role there.
Tungsten is also extremely refractory for a metal. That might make it useful for tools in high-heat situations, if you didn't mind the tools being really heavy.