Are you going to use the key items now? That's the real question...
I'm unfamiliar with smithing (I'm a cook) but I've only gotten 1 key item for cooking...Raw Fish Handling. I got it in the early 60's, because I wanted the ability to make my own Sushi. However, I noticed after I got it that the price of Sushi was already skewed somewhat towards people HQ'ing it, so with breaks and such I actually lost a little money compared to just buying it off the AH...so I don't use it very much TBH. I will when I get higher and can HQ it more regularly, but for now, meh...
So, like I said...if you're actually going to use the key items, then go for it. Otherwise, wait as long as you can, so that you'll be higher level and be able to turn in HQ items for more points and save yourself some gil.