I paid $1500 for my used Wehman camera because I wanted to carry it into the field. Like said earlier you can get an 8x10 for a lot less but of course there are always compromises in movements or portability or something which may or may not matter to you. I paid $600.00 for my 14" Kodak Commercial Ektar lens. A 14" lens is close to a 360mm which is considered a "normal" focal length for 8x10. Of course you can pick up a 250-300mm cheaper. A lot of photographers use a 300mm for 8x10 portraits. I paid almost $300 for my Fuji 250mm f/6.7 lens. It's nice for environmental portraits. Long lenses in shutter can be quite pricey. As mentioned earlier lenses in barrel can be much cheaper. New film holders are $200 a piece. You can buy used ones off Ebay for around $40 a piece. As far as film prices go, well I only shoot b&w with 8x10. I have a 4x5 for color.
I read that Richard Avedon used a Schneider 360mm lens for his American West series portraits. Also check out Yousef Karsh's work using a 14" Commercial Ektar.
I just wanted to give you some prices on things. I don't want to discourage you though because 8x10 is a lot of fun.