Original stocks are available from time to time on ebay, auction arms and gun broker. One will likely cost you $200-$300, although I haven't been watching lately. Repros can be had from around $150(need fit and finish) to $300 drop in. If you keep your eyes open and are patient you can likely do better on the $. If you don't want to get into it drop me a line and I will take over the project!!
Regards,
Ned