yeah, a dual tower is maybe 150 - birdman has them for 104. - the fridge another 150 at most. the kegs maybe 70 bucks. Lines and Co2 tank - another 100
800 is very high. I doubt I spent more than 400 on my 6 tap setup.
one of your kegs does look brand new - I know new ones are expensive but you can buy used ones on craigslist for 35-45 dollars.
you might have better luck parting it out.
sorry, just trying to give you what I think is a realistic viewpoint.