The coas to replace 6 windows will be prohibitive. As others have said, they can be repaired. There are several companies that do this - one is in Arkansas, one id in Florida, and I think there is one in Indiana. The cost to repair if the glass is not etched, which happens if the fogging is allowed to go for a long time without repair, is about $200 to $300 per window depending on size. If the glass is etched, it will have to be replaced at an additional cost, but it will still be cheaper than replacing the entire window.
As az bound says, there are also DIY kits, but you need to be able to remove the windows, take the frames apart and separate the rubber seal from between the panes.
We have had all but one window on our 2005 Allegro Bay repaired at Suncoast Designers in Hudson, FL. We are happy with their work, and they have a pro-rated, 10-year warranty.
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