@ten6mom - regarding your question on DVC, in order to answer this I'm going to take you back to my buying experience with regard to price per point and cost of vacation home rooms, versus hotel rooms.
In 2000, points at BWV were $67 a point and the incentive in Nov 2000, was if staying at a Disney resort, they would credit 1/2 your room stay total to the purchase.
In addition to that, a couple of months earlier I became a
Disney store part time cast member. I had been going to WDW for a dozen years (1988 first visit as an adult) and I was smitten. This job was very very limited, paid $6 an hour and they'd call you in for 2-4 hours 2 or 3 times a month on the weekends. Most part time employees were teachers, which is how I made my connection and got into it.
This gave me 15% off DVC bringing $67 to $56.95 in addition to the incentive from 1/2 my Polynesian room cost.
Dues at BWV in 2000 were $3.94 per point. A Sunday through Thursday studio cost 9 points in Adventure and Choice season. So after buy in, the room for 5 nights would cost 9 times 3.94 = $35.46 or for the 5 nights $177.30. The buy in added to this total also, but I want to make the important point that maintenance fees are the larger cost going forward. In contrast, my room at Polynesian was over $300 a night for the concierge building which I really loved and had a hard time giving up.
Fast forward to 2020. Now, prices for new resorts have tripled or quadrupled. Deluxe (that's questionable) Hotel rooms have also increased significantly. Dues in 2020 for BWV are $7.36 per point. Not quite double from my buy in point. And, occasionally I get a bigger room which costs more points.
For my situation (and for other BWV owners, reallocation - a tool that Disney frequently uses, has helped with that standard view studio. I almost never went on a weekend my first few years, as weekends were so much higher. 85 to 87 points for 7 nights versus 76 to 78 points after reallocation for 7 nights. So now, I'm staying longer, helped by Disney, plus adding more points and contracts at other resorts.
For me, it worked out really well.
For you or your sister, you deal with today's numbers and whether it will save you money. You have to analyse the cost over time and understand it won't stay the same. If you stay offsite happily and pay $100 a night now, are you willing to pay more for the onsite advantage? If you stay Grand Floridian CL level suites now, are you ready to take a cut in accommodation? (VGF are nice but so limited getting in is very difficult.)
Another factor is how long you plan to keep it. Lots of people do 5-10 years and are done. Others are 'lifers' like probably me.
It 'can' dip in price and cost less when you go to sell. In general most people have gotten their buy in money back on sale, but maintenance money is gone, as it should be.
I had toured quite a few timeshares before I bought - spent 3 years from learning it existed to pulling the trigger, making it a deliberate act for me. Just the viewing experience was light years apart in how timeshares are sold. Plus they bought me and 4 others in my party, lunch at Spoodles - now Trattoria Al Forno.
It's been a great ride for 20 years for me. I think the experience so much depends on what you want from it. I still get a little thrill pulling up to Boardwalk.