A Fortune Lv7 gives a flat 15 attack power to Hunters and a 10% crit chance.
1.5 * (15) + 1.5 * (15/2) = 33.75
That's a 90% chance of adding 15 attack power and a 10% chance of adding 33.75 attack power. Averaged out, that's a gain of 16.875 attack power. If you look at it like that, yes, the Craft Lv5 is better, but you're not just critting on the 15 attack power from the Fortune Lv7, but your entire attack power. Using 2000 attack power as an example, and adding either a Craft Lv5 or Fortune Lv7:
(0.9 * 2015) + (0.1 * (1.5 * (2015) + 1.5 * (2015/2)) = 2266.875
With a base attack power of 2000, which is not difficult to achieve, the Fortune Lv7 is superior by nearly 250 average attack power per hit. That's the equivalent of 17 levels of enchanting. So is it really more cost effective? A bow/jav with a Fortune Lv7 linked is as effective as a  bow/jav with a Craft Lv5 linked.
Your best bet is to max out your links. Lv7 Craft, Fortune, Shrewd, and Life wherever they can go. If you're not doing that, you're just robbing yourself of stat points. Even on pieces that can take all four of those (mufflers are going to be rough), that leaves two slots per piece for Sonics, Eles, Absorb, etc. The only thing you may consider doing differently is the weapon, where you'll needed to decide if Dex/Luc or attack power are more important to you.
But no matter how you look at it, 800 Luc 1200 Str is going to out-perform 450 Luc 1350 Str.