At least $3k and getting more difficult to obtain, esp. 9L4 distributors (don't recall prod. date of this car). One of the factors in buying mine was that it had all the right stuff. Do we even know if this is a numbers matching block yet (I've lost track)? I see the one "S" I'd like to see Sloan Docs - Why would anyone sell these cars w/o when it's so easy/cheap to get even though in this case it's Stage 1 pedigree isn't in doubt. The trunk floor is amazingly clean compared to the rest of the rust unless it's been patched up.
Lest we forget a nice 1233000 big block fan shroud. Sure you can get one for $500. But a nice one will run 2x that money and deservedly so.
At least 6 or 7 year ago. When I had the car it was complete correct everything except the fan shroud which had been replaced due to a drivers side front end collision. It needed 1/4's, trunk pan, doors, passenger side fender and inner fender. The drive train is numbers matching but the vin tag on the dash shows the car as a Skylark 444 not a 446, car is certified by Wayne as a real Stage 1 but due to a factory mistake the vin is wrong. As I recall the title was a 446 title. In my home state all older cars have to be inspected for numbers by the DMV enforcement officer and that is why I passed it on. I informed the new buyer who was in Connecticut of all the title vin issues and he said he could "fix" it.
There was a similar situation on a Stage 1 that for sale in the Boston area a few years ago but IIRC, the the engine (may have been the VIN) had a wrong digit. One of the Stage 1 convertible 4-sp. cars @ Mecum a couple had a wrong digit in the engine stamp.
This same car came up on a Craigslist ad in Boston a few years back and I told the same story. At one time I considered having the title changed to match the vin. It would then be the only Stage 1 455 Skylark built....