It would depend on many things. type of image, dagguerrotype, Amber or tin, ferrotype cdv. Subject matter, is the person armed, Corp badge or other I’d emblems. Is it Id’ed with a name or unit etc. some times the cases are worth more then the image themselves. Especially larger thermoplastic union cases. A run of the mill tintype or cdv usually are quite affordable depending on where you buy. If a large or expensive purchase go with a established dealer. Save yourself headaches and troubles! Post a pic of the image if you have one many experts here! Lots of information!! But saying a ballpark price is quite difficult! So many factors