Gotcha, that is weird pricing since National, Alamo and Enterprise are owned by the same conglomerate.
Several here have suggested Costco for good car rental codes / rates.
I understand collecting WN points but *think* they are relatively small and fixed per rental while at least National give you credit based upon length of rental. They aren't points per se but credits towards free days. But it sounds like the last thing you need is more rental cars!!