CSR rack rates would be $149 weekday, $159 weekend with added tax. Price quoted by Disney website for 7 nights in September for 2 room totals $2392 ($2126 + ~$265 tax). So 35% savings would be ~$837. Assuming that all childern are greater than age 3, for 7 nights, dining plan would be ~$790 ($39.95*2+$10.99*3 per day). If math is correct, 35% discount would save ~$47.
I've never stayed onsite so this is more a question than a statement...Does the percentage off the rack rate include the % off of tax. That would suprise me if it does. If that is the case, then it would save less.