I would go with the used machine. Computerized parts last a long time. I really don't think they are subject to any more stress than metal moving parts. If they've lasted 8 years, there's no reason to think they won't last for another 20 years. Plus the dealer has a vested interest. I wonder if he would give you the same warning if he had a used MC6500P in your price range to sell you? My 2 cents......