That one is that expensive because it's made by Larue. They make some damn good stuff, but they don't just give it away either. You should be able to find one made by someone else for much cheaper, and if you don't need the Quick Throw Levers, that should bring the price down as well. I just posted a pic of that one because it was the first thing that popped into my head.
"Breathe when you can, shoot when you should."
"Qui desiderat pacem, bellum praeparat; nemo provocare ne offendere audet quem intelliget superiorem esse pugnaturem"