Sellers are asking $500.00-$600.00 all the time for clean late model Crown Graphics on ebay. Notice that I said asking. I don't know if any are selling for that.
I recently paid $400.00 for my late model Crown with Zenar. It came with some mint film holders. It took me awhile to find one for that price in the condition I wanted. It's worth paying extra for something in nice shape than buying something cheap that is worn out.
I bought my Crown for outdoor portraits. It's got the Schneider 135 Zenar. I also added a Caltar 210 lens. It's great for the portraits that I plan on doing with it. Environmental, full length or 3/4.
You mentioned close-up portraits. If you normally use an 85-100 lens for portraits on a 35mm camera then you probably would want a 300mm on a 4x5. The problem is that you can't close focus a 300mm on a Crown down to a portrait distance of 5-6 feet.