I only did Nationals once, and took 2 totes - carried my shoes with me. Checked them in, no problem from the airline side other than one of the zippers getting destroyed. Lugging them into/through the airport was a PITA.
After bowling, I checked into Fed Exing them home. They had a place right there in the convention center - boxed em up for me and shipped them.
I don't remember the cost, but for me it was worth every penny to not have to drag 60 more lbs of stuff through the airports. I'll never fly with bowling balls again (but then, I don't like dealing with airports anyway. Everything before and after the actual flight just sucks). Anyway, just figure the shipping into the overall cost of the trip and enjoy not having to deal with them off the lanes.