You'll never be able to justify
DVC (financially) if you intend on staying at the non-DVC properties with regularity. For the occasional "fix" it might not be so bad. At least the option exists.
But most times of year I wouldn't be surprised if the number of points required x annual dues is already more than the Rack Rate (or at least AP holder rate) for those Deluxe resorts.
I know people have attachments to those monorail resorts, but IMO you're really doing yourself a disservice if you discount DVC simply because of the location of the resorts.
Over the past 5 years, point costs have risen from $65 per point to $95 per point--a 46% increase.
If you want to be in close proximity to theme parks, consider a resale purchase at the Beach Club Villas or Boardwalk Villas which are walking distance (or boat) to both EPCOT AND MGM.
A One Bedroom DVC accommodation at BCV or BWV for 6 nights, about 5 months out of the year (DVC has multiple "seasons" with different point costs) would require about 167 points. BWV has current-year annual dues of $4.25 per point, meaning this stay would cost you $710 out of pocket. No tax. No additional fees.
Now, I don't know what sort of travel habits your family has, but I suspect you are paying more than $118 per night for accommodations at the Poly or CR. And with a DVC 1B, we're talking about a room that is a significant step up from a standard Deluxe resort room--full kitchen, in-room washer and dryer, separate living room and bedroom, two TVs, DVD player in living room, balcony, whirlpool tub in bath, etc.
My children are 3 and 1, and to ME, a vacation is knowing I can lie the kiddies down for a nap in the bedroom and still watch TV, relax on the balcony, or just carry on a conversation with my wife.
If you're satisfied with a room comparable to the Deluxe room, a DVC studio would be a better match. A studio for those same 6 nights is only 83 points ($353 with BWV dues, or $58 per night). And on the amenity side, even the studios come with a kitchenette (mini fridge, sink, microwave, paper/plasticware), a balcony and free access to public laundry facilities.
Of course you do need to factor in the initial cash outlay for DVC, but most people who run the numbers find that the DVC break even point is anywhere from 6-12 years (depending upon individual factors like travel dates, room types, etc.)
So my question to you is whether you can afford NOT to buy into DVC? Are the poor trade-in values of the Poly and CR really worth that convenience factor? Think of the thousands of dollars you've spend for WDW resort rooms in the past 5 years, and how far they could have gone toward paying for your WDW investment.
You know you'll be back to WDW with regularity. You know the DVC prices will only increase. You can get into Saratoga Springs now and enjoy WDW for the next FIFTY years. And, when you need that Poly or CR "fix", yes, you can still use your points there--the value just isn't as good as at the DVC properties.
One last thing to consider--if you take a gander at the DVC point calculator, one thing you will quickly discover is that weekend point costs are often 2x or higher those of weekday nights. Many DVCers will use their points to stay at the DVC properties on weekdays and then pay cash for the weekend nights that are part of their vacation schedule. You may want to consider a plan that would have your spending weekdays at a DVC resort, and then you could pay cash to get your monorail resort "fix" on the weekends. WDW resorts will move your luggage for you, making it a pretty painless process. The only inconvenience is that you may be without a room for about 5-6 hours from the time you check-out of one resort until check-in time at the other.
A lot of food for thought. I really hope you give this a look, and keep us all posted on your decision!
