I don't put too much effort into crafting professions, for the most part. Something like Inscription, where I can get a number of points by just remembering to research once a day, fine. But Blacksmithing or Engineering, with stacks of metal per point? Not for me. (The exception to this is Tailoring, which I keep on my priest more out of tradition than anything else.)
Engineering is another profession that seems to take a lot of work per point (although I haven't gotten it very high myself, so I can't speak from first-hand experience here). On the other hand, there are a lot of really cool gizmos engineers can make for themselves, from hand rockets to motorcycles.
One of those gizmos is about to get significantly more useful: the Scrapbot will be able to repair your gear "in a future patch." The smart money is on 3.0.8 for that future patch, since Scrapbot repairs were added to the latest build of that patch on the PTR just yesterday. This means that once again, Engineers are the providers of in-instance repairs, and this time around it's significantly cheaper than last time, with 10 Saronite Bars giving you 5 of the little guys. And they're so cute!