I recommend you look for a blued steel or stainless steel framed Remington 58 NMA over the Brass frame Buffalo. A steel / sts frame will allow you to use 45 Colt Conversion Cylinders if you are so inclined, down the line.
Pietta's frequently go on sale at Cabela's:
http://www.cabelas.com/catalog/browse.cmd?N=1115136
Otherwise keep an eye on Dixie Gunworks, they occasionally have sales:
http://www.dixiegunworks.com/default...=22_92_187_189
Lastly check on Gunbroker - I recently bought a used Pietta 1860 Army from there. It came with a conversion cylinder and was right around the same price as Cabela's:
www.gunbroker.com