A like Anatares's advice...check the pattern on Raverly and check out what yarn the other knitters used. I do that all the time.
Sometimes it's a double-edged blessing...you might stumble upon comments that exposes the faults of a particular yarn you might have used otherwise.
Sometimes you see some variegated yarns used for your intended pattern...and you can clearly identify why you wouldn't want to use it!
Below is a screen shot of the page header you'll see when you click on PROJECTS for your particular pattern. See the tab called YARN IDEAS? That's a good resource. And if you click it, the next page will tell you all the yarns the other knitters used, and how many times knitters used a particular yarn. For example, Lion Brand Fisherman's Wool was used by 7 knitters. It is not an expensive yarn. And you can look at their results! No doubt, it's just as nice at the yarn that would have cost $150.
Anyway, just sayin....