According to "Flayderman's Guide to antique American Firearms", 9th Edition (2007) an original 1860 Colt Army model with military markings in "good" condition was worth $950 (US). In "Fine" condition it was worth $7,500 (US).
About 1 week ago there was a Walker pistol on the Swedish Tradera.com (Swedish Ebay) that the seller claimed to be an orginal for 35,000 Kr ($4900 USD).
Everyone said it was an obvious fake but the seller claimed that Flyaderman said it was real but only that it had a replacement cylinder.
Who would sell such an original 1847 Walker for under $5000, or should I ask who would buy it?
So I guess that Swedish buyers should beware even though there are some really nice antique guns over there.