The New Army sells for around $245.00 right now. But that is new. When I was asked if I wanted to sell my 1858 New Army Remington Target Model I asked $175.00 only because I too had lots of extras to go with it.
I have had excellent luck with my Army target model. A real good shooter. And just a lot of fun to shoot. But I have heard "stories" if the Pietta cylinders being off lined and spraying lead back at the shooter. And I am sure this could happen.
The value of it is what you think you want to pay and how bad you want it. I am sure if he owned it a long time, he probably paid around $129.00 - $159.00 new for it. With lots of extras, if you could get it cheap, it sounds like a good deal. Bit not seeing the revolver, it would be impossible to say... X dollars. They are a lot of fun to shoot. And there are ways to clean them that really speeds up the process.