I think it depends on what you are trying to achieve. Personally I value starting pitching way more than relief pitching, but it looks the key to your league pitching wise is to get as many good relievers at the expense of starters.
I tried to evaluate some stats in a fantasy league last year with the intent of keeping hitting and pitching 50% each. The hitting categories are pretty easy to come up with (though I don't value a stolen base the same as a double

). From there I had an approximate # of points that the pitching should total with certain categories. So I then came up with a relatively arbitrary value for a bunch of pitching categories so that at the end of the season points scored by pitchers and hitters will hopefully be 50%. Once I came up with that number, I had to figure out how to value each category. From my view, closers are overrated and the guy who throws 200 innings is pretty important. I think the biggest flaw in the system below is how much wins are valued, as well as quality starts given that 6 innings and 3 ER is merely a 4.50 ERA. However, it hopefully will accomplish the goal of valuing starting pitching a great deal.
The point system in my league:
Single: 1 point
Double: 2 points
Triple: 3 points
Home Run: 4 points
Run: 0.5 points
RBI: 1 point
Walk: 1 point
Stolen Base: 1 point
Inning pitched: 1.5 points
Win: 16 points
Quality Start: 12 points
Save: 7 points
Complete Game: 4 points
Strike out: 1 point
Hit allowed: -1 point
Walk allowed: -1 point
earned run allowed: -3 points
Blown Save: -3 points