For the record, Octane + a Titan card is TOTALLY worth it, if you can afford it.
Octane improved the quality of my renders tenfold (at least). I had given up rendering for several years because I didn't feel like I could get a realistic enough look. Octane changed that.
And the Titan (I got a Titan Black) increased my rendering speed (from my GTX 680) by a factor of 4-6. A 36 hour render dropped to about 6 hours.
I'm not sure the Titan X is better than my Black enough to justify an upgrade. More CUDA cores, more memory (I have actually run into memory issues when rendering multiple characters when using my 680+Titan to render) and slightly faster. But another $1,000? And I don't think my machine can power 2 Titans...