Judy, I compare apples to apples when I figure my savings. We wanted Deluxe Vill Resorts at the best possible price, so that's what I'm comparing to, not dropping down to a mod. My family is me, DW & 9 year old DD
If you look at just Kidani Savannah View alone right now for the time I'm staying, WDW is publishing $507.37 per night (x 7 = $3,551.59), which is probably the rack rate you will pay for FD. By renting points my nightly rate averaged out to about $210 per night (x 7 = $1,470). <$2,081.59 savings>
Next, I purchased 5 day Hopper passes through
Undercover Tourist ($1,006.44 vs. WDW price of $1,091.63 which you would have to pay with FD)<$85.19 savings>
Finally, we are the Basic Dining plan for all of us at full price ($950.40), but I'm paying with gift cards I got at Target at a 5% discount, so $905.73 really. So my total for a week is $1,470 room + $1,006.44 tix + $905.73 DP = $3,382.17, which is lower than just the rack rate of the room we're getting.
I hope this helps.