I use extended VGA cables on a regular basis. I have had good luck up to about a hundred feet. Very minimal loss. However, the cable should be of high quality. You should be able to buy a decent 75' cable for about $40-$50. I typically pay about $20.00 for 50ft VGAs, and yes, the quality is good. Try MilesTek
www.milestek.com, or Cablewholesale
www.cablewholsale.com. There are a million other sources on the internet with similar prices. I would stay away from Belkin or Monster.