The DWG files give you an idea of what the finished the design looks like but only gives an orthographic view. I'm thinking the places that gave you a quote are estimating the time it would take to create this model and translate it into G code, which is what most CNC routers use. There is another way, but you have to create a graphic that uses black and white gradients in order to create a cut pattern. However, it may not come out as exactly how you have it pictured. Is the first picture you have posted, something you downloaded off of the internet, or is that your "master"?
If you can create your design in something the CNC router can read directly, this will most likely lower your cost greatly.
TazMan2000