Yes! No! Yes! On the one hand, writing conferences are really inspiring. You get to meet other writers and network with industry professionals (agents! editors! yay!).
On the other hand... money.
There are zillions of ways you can spend money on writing. You can take classes and workshops to learn the craft. Attend conferences for the reasons listed above. Learn, learn, learn. Network, network, network.
Remember, though, writing is about writing. Getting words on paper. Saying what you want to say in your own voice. Much of that will happen for you if you just stay home and write.
But that's not to say conferences aren't worth the investment! Just choose wisely. And don't go into debt for a conference you can't really afford. You'll get just as far in your work by writing as you will by dishing out cash for a conference.