OK, here's Mark with the new saw. He checked into renting concrete cutting saws (circular saws) and hiring it done. It was cost effective for him to purchase this saw and do his two windows, two at his dad's then sell it. Even without selling it he's better off. It was something around $1300 and is a chain saw with diamond teeth. The chain alone is $300 but he was told he could get the four windows cut with only 75% of the chain.
The unit is Italian made by ICS and has a hollow bar through which water runs. It hooks up to a garden hose. Very messy, but very effective. You score your cut line with the nose of the bar. Then go over it again to a depth of two inches. Then make a plunge cut and follow the score line. Big advantage is no overcutting necessary to make the corners. His windows were four feet square and the four sides took a total of about an hour to cut. He said it was pretty tiring holding the saw, particularly on the horizontal cuts /forums/images/graemlins/smile.gif