You will have to contact Remington.
100-500
Contact Remington on their web site. Your question is impossible to answer without the caliber of the rifle
www.cabelas.com www.cheaperthandirt.com proably eBay
$400.00
1500.00
About $250, depending on which version and condition.
codey
It depends on what caliber it is chambered in.
http://remingtonsociety.com/rsa/questions/barrelcodes
100-1000 USD and up depending on specifics
100-300 USD