I would agree with others who have suggested that DVC is not a good fit for you - at this point in time.
1. DVC should be used at least every other year. If you start doing once every three years, you risk breakage on points (points expiring unused)
I do not know how you can do 1 out of every 4 years in a 1 bed room, you can only have three years worth of points available at one time (unless you do the exact week that spans use years)
2. If you are content staying off property, and there is nothing wrong with that, DVC probably isn't for you. There are some great resorts off property - Hotel Plaza Blvd, Bonnet Creek (even timeshares you can rent there) that will be significantly cheaper. The only reason people like myself do not go that route is that I drank the kool-aid and "need" to be on property. If I didn't I would probably be in one of the two aforementioned areas.
3. You can rent DVC rooms and save good money off of rack rates, if you really want a DVC resort.
Also, 4 days is just too short of a time in my opinion. You can not cover all of WDW in 4 days. and with what it takes you to get there, 8 days just makes more sense.
I am now going to disagree with someone I normally agree with spot on. I do think that you should not view DVC as an investment or something that will make you money, or anything like that. That being said, I do not think the resale market is being destroyed. I do think DVC contracts have held their value quite well even with all the other changes. BCV contracts are listing in the 135-150 range. For a 2042 resort! I got VGF for 150 and that was for 50 years, not 25. As long as Disney keeps jacking up rates for sold out resorts, the resale market will be vibrant. The big X factor is this new restriction that Riviera is seeing where points on the resale market are only good at Riviera. It might change their value, it might not.
Overall, I think you should wait on DVC