We are just closing on our first
DVC resale contract. We are very happy with paying outright with a resale contract and getting it for almost half of what it would be compared to direct through DVC -- I would strongly consider this. You may not get poly resale but you could get your feet wet with a SSR, AKV, OKW smaller contract and see how you like it and not take such a financial hit. Aside from the monthly loan payments you also have yearly maintenance fees to consider. Those can be paid either the whole amount in January or monthly payments (direct draft from checking account).
One great tip that i learned from the forums is to buy discount target gift cards on raise.com, to then buy Disney gift cards with the target red 5% discount. you can get a combined savings of easily 10-12% and those gift cards can be used to pay yearly Maintenance fees.
A direct 100-200 contract is going to cost between $16500 and $33000 - you could purchase an almost 200 points resale for less than your 100 point direct contract. Many people can make back some money with renting their point, say if you didn't use all your 200 points.
Just as a side note -- there are financing companies that will finance a resale and i think the % rates are close to if not better than Disney direct.
You mention that your BF has credit issues. Hopefully his debt is paid clear and that is no longer an issue. It takes awhile to get your score back up so you would probably get a better financing rate with just yours. You could always have them run the credit with both. Although i think many are secured loans with the timeshare as its collateral, so very possibly that his credit won't be that big of an issue.
Just a word of caution -If you are the only named person on the loan and deed then if the relationship goes south (i'm not saying it will) then you are stuck with the payments yourself- not him.
Also you noted putting the down payment with a credit card. I don't want to sounds like a downer but I would save up your down payment and then take the plunge. If you have the money to pay it right off away then great -- this is a good way to earn some $$ in a Disney gift card.
This is a very exciting purchase to make and sometimes you can get wrapped up in the excitement that the financial reasoning side of your brain just doesn't think clearly. You need to think of your long term goals and financial commitments. This is an entertainment item and for us if we couldn't pay outright we wouldn't do it.
I wouldn't rush to make a direct purchase for your December trip -- December is a high demand month for DVC and likely there aren't many if any DVC rooms available. Maybe on your December trip you can ask to tour some of the other resorts to get a feel of what is available.