Thanks, Kim.
I hadn't thought about the differences in nutritional value. After doing some checking, they all seem fairly close, with the exception of arrowroot. That does seem to be higher in quite a few things. Sweet! Now I won't have to have umpteen dozen flours and starches roaming around my fridge.
As for cost, (well, my cost), they're pretty much the same except tapioca flour is very inexpensive - 14 oz for 59 cents. Everything else is 14-16 oz for $3.50 or more.