Can't help you with a value, but considering the condition and the box and paperwork it may be worth more to a collector then someone looking for a range blaster.
I bought a case hardened Colt new frontier buntline .22lr with the extra mag cylinder a while back for around $400 but it wasn't quite as fresh as that one and didn't have the box only the small instruction booklet.
Fun guns, slightly scaled down in size and no transfer safety only the half ####.