Neither of those options may be the cheapest way to go. If you're really interested in doing the vacation on a shoestring budget, then look at offsite properties for more space and lower costs.
And don't bother with the pass upgrade unless you plan to go back to Disney World again (for a long visit) before they expire. Each Premier Passport costs $871.75 after tax. How much did you pay for your DL AP? You will have to pay the difference in cost, which may not be less than the cost of MYW passes with hopping if you purchase from a reputable ticket seller like Undercovertourist.com.
The Swan and Dolphin are not Disney hotels, and you will not get an AP discount if you stay there. But you can get an AP discount on any of the Disney resorts most of the time. Even with the discount, it still will not compare to staying offsite when it comes to the amount of space you get for your dollar.
And renting DVC points is not as easy as some people would make you think. The rooms with the lowest points per night are snapped up 11 months in advance by DVC members who own at those resorts. You are not going to get a value studio at AKV any time after that unless the gods smile upon you and someone cancels just at the exact moment that the owner you are renting points from inquires about it. And even if that does happen, you will still spend more for that studio room than you would for a room at a value resort for the same period of time.
My advice for going on a limited budget:
- Sign up for the Mousesavers.com monthly email newsletter and then use the link in it to get a better discount on Undercovertourist.com's tickets.
- Look at offsite resorts for cheaper accommodations. Check Tripadvisor.com for reviews before you commit to staying at any of them. Use Hotwire or Hotels.com to book for the lowest possible cost.
- Bring a packed lunch but also make plans for a dinner break at one of the restaurants in the parks. That way, you won't feel deprived but you will save yourself a few $s on your dining costs.
- Set a souvenir budget and don't go over it. It might help if you put your souvenir money on a gift card just to help keep track of your spending.