OK. I'm over-simplifying it. Maybe there is an exception that you can make competitive decks w/o having to spend that much, but unlikely. Ultra rares will be the most powerful cards.
My guess on how much it takes to build a complete set is probably around $300-$400 per set; probably on the low-end of the spectrum. However, there will be duplicates, triples, or 4x of ultra rares that you need-unless the rules state you can only have 1 of each card. So I'm guessing you'll be spending $1000-$3000? to be competitive at Nationals/Worlds for the core set?
I would love to hear your thoughts.