Something like $3500
http://www.sig551.com/
"The original 250 SIG 551s used in this project were owned by Sig Sauer but were being stored in a Swiss bonded warehouse. What we are being told by others in the firearm community is that these rifles were not able to be transferred due to some type of NFA paperwork snafu. West Coast Armory had been contacted by Sig Sauer several months ago about these rifles, and at that time we offered to purchase every one of the SIG 551s if there was a way possible of making them into Sig SG551s. When Sig Sauer called back and said there was a chance for the SG551 to be produced, West Coast Armory immediately sent a large deposit to start the project. At that time we also had assurance that we were buying the last of the SIG SG551 rifles Sig Sauer will have available - ever.
What makes this rifle unique is that it is completely made by Sig Sauer, we had nothing to with the physical production or building of the rifle, it comes with the Sig Sauer limited lifetime warranty and a serial numbered letter of authenticity from Sig Sauer stating it is 1 of 250 SIG SG551s they built. Yes they are SIG 556 upper receivers, but their model number is SG551 and the serial number was matched to the original number of the demilled SIG 551. Being a long time SIG enthusiast and collector, I tried my best to get the rear sights from the demilled 551s, but almost all of them had the railed receiver. We were required to use the standard SIG 556 Barrel and upper for the 922R parts count. I also tried to have this changed, but it would have added some serious costs to the rifle. 250 rifles are not enough to cover custom manufacturing from a company like SIG. The sample rifle is a very tight fit, no movement from the upper to lower and the sight base screws are recessed."
http://www.sig551.com/
"The original 250 SIG 551s used in this project were owned by Sig Sauer but were being stored in a Swiss bonded warehouse. What we are being told by others in the firearm community is that these rifles were not able to be transferred due to some type of NFA paperwork snafu. West Coast Armory had been contacted by Sig Sauer several months ago about these rifles, and at that time we offered to purchase every one of the SIG 551s if there was a way possible of making them into Sig SG551s. When Sig Sauer called back and said there was a chance for the SG551 to be produced, West Coast Armory immediately sent a large deposit to start the project. At that time we also had assurance that we were buying the last of the SIG SG551 rifles Sig Sauer will have available - ever.
What makes this rifle unique is that it is completely made by Sig Sauer, we had nothing to with the physical production or building of the rifle, it comes with the Sig Sauer limited lifetime warranty and a serial numbered letter of authenticity from Sig Sauer stating it is 1 of 250 SIG SG551s they built. Yes they are SIG 556 upper receivers, but their model number is SG551 and the serial number was matched to the original number of the demilled SIG 551. Being a long time SIG enthusiast and collector, I tried my best to get the rear sights from the demilled 551s, but almost all of them had the railed receiver. We were required to use the standard SIG 556 Barrel and upper for the 922R parts count. I also tried to have this changed, but it would have added some serious costs to the rifle. 250 rifles are not enough to cover custom manufacturing from a company like SIG. The sample rifle is a very tight fit, no movement from the upper to lower and the sight base screws are recessed."