Gonna be real, the collector booster seems like a complete rip off. Verses normal boosters, it's only offering 2 foils against 20 commons. I'd rather buy 3 normal packs.
I draft like twice a week. Commons are like kindling to me. I would trade 20 worthless commons from a recent set for any random uncommon from the same set. Guilds of Ravnica doesn't even have any "chase" commons like an Opt or anything to make the common slots worth anything.
Really, that one extra dollar factors much more into my calculations than any number of commons.