Perro,
Depends on what you define as "expensive". I have an original on my '66 stepside and I think I paid $100 w/shipping 3 years ago. I was happy with the deal.
Got another one from a fellow bolter who had one to sell off a parts truck. I paid about the same for it. I got the extra aluminum grille because.
a. As others have said they are not re-poped, and are no longer available new. That makes for short supply and higher prices over time. Might as well snag 'em cheap whenever you can.
b. They don't rust out like the cheap aftermarket steel mess they're making today. I bought one of those about 5 years ago for $175 and it's still sitting in my garage unused. I guess they're okay for non-original show truck, but for a daily driver they're guaranteed to rust out in exposure to the elements.
c. Just in case another large doe decides to jump out in front of my truck at 60 mph, just as happened with the original one. (By the way, the grill and a smashed headlamp was the
only damage to the truck. The doe didn't fare as well

).
-ftyler