Disney's interest rates for good credit scores are ridiculous enough, i can't imagine anything that would justify paying an even higher rate. Look at the numbers, and consider whether the costs of financing will wipe out any potential savings you'd have on your lodging. Try renting points instead for awhile instead, and put the money you would have thrown away on finance charges towards buying your own DVC membership without financing someday.
Alternatively, look at the resale listings. Pick up a small contract, one that you can afford without financing. Use banking and borrowing, and you can put together a nice trip every couple of years. You can add on when you've got the money to do so.