I'll handle each separately then a conclusion ( of sorts) at the end.
DVC. (Disney's answer to timeshare).
Disney's use of a point's scheme makes this a really flexible option for most peoples vacation needs. There are 4 sizes of unit that sleep 4 ( in a hotel room size unit), 4 (in a one bedroom suite with full kitchen and living room. The bedroom has one Kingsize bed and a pullout sofa bed in the living room), 8 ( in a two bedroom unit, which is basically both of the above joined together) and 12 (in a 3 bedroom Villa, at least one sofabed makes up the balance of beds !!). The cost, in points, of each unit varies with the days of the week and the seasons. You can go WHENEVER you want in the year and take whatever size unit you want AS LONG AS there is availability and you have the points available to use.
You are given your certain number of points each year and have a points " use year" in which to use (or bank them). There are restrictions on banking and borrowing points but these are pretty fair/flexible so as long as your fairly organised it shouldn't prove a problem to anyone.
Cost. Minimum is 150 points which are currently $67 per point through Disney, cheaper by resale. ( 150x67= $10,050) as A ONE OFF PAYMENT and thereafter you have to pay " dues" which are about $4 per point at the moment ( these have historically averaged about 3% PA increase) so at the moment dues would be about $600 per year. What would 150 " buy you as far as accomodation goes ? Well in August that would get you a "hotel room" type unit for 11 nights ( consecutive but only using one weekend as they are MUCH more expensive). The are so many different ways to use your points I would suggest looking at the points chart on the DVC information page which is on
http://www.wdwinfo.com/resort/dvcpoint.shtml and playing around to see what suits you.
What I think is so good about the points system is, when your kids are small you can get away with a " studio" and have longer stays, as they get bigger ( if they can share the pull out) and you don't want to be sharing a room you can use a one bedroom. Want to bring Grandparents? or you have more than 2 kids ? get a 2 bedroom. Fancy a family holiday with Grandparents and your brother/sister's family? Save up you points and get a 3 bedroom. Kids have all flown the coop? get a studio and have a long time there. Become grandparents, take your children and their family and get a two bedroom. It is a system that allows your family to grow and your needs ( time of the year) to change without penalising you.
IMHO between 200 and 300 points should be enough for most people's needs UNLESS you want to stay exclusively on Disney for 3 weeks EVERY YEAR in a larger unit. There are a lot of ways to make the most out of your points and I prefer to use the DVC as " a little extra treat" within a holiday not as my exclusive destination. There are many that prefer to stay on DVC ALL the time, to each their own.
Owning a house
Obviously this is a bigger commitment and really IMHO should only be looked at IF your concidering spending A LOT OF TIME in Florida in the future. I do plan to retire there and spend AT LEAST 4-6 month each year there when I do. US immigration rules at the moment allow you to spend one day short of 6 months each year without becoming resident, more than that you have to get a green card, which isn't easy !!. As an investment, your not going to get rich on your rental earnings and IMHO if you do better than break even then your doing well. As far as property prices in the future..... Who knows, IMHO they are likely to rise as the population ages and more of that generation have the money to either have a holiday home in a warm climate or just plain go live there all year round.
Cost
A nice 3 bedroom house not too far from WDW start from about $100,000. You need to be able to come up with about 30% as a downpayment, allow $15,000 to furnish it AND leave about $5,000 for closing costs. You should get some money back from that $50,000 but I wouldn't bank on it LOL . Your mortgage on the balance is likely to be about $800-900 and your agents "costs" about the same so your earnings need to be about $1600 a month to break even. The reality of that is you need to be rented out about 23-24 days a month to break even. Or if you prefer 38-39 weeks of the year. So far my house has been a little shy of these totals and has cost me $3-4,000 each year. But I have had 5 weeks use at PRIME rental time and would certainly have picked up bookings for all those times and would expect to have earned $2,500-3,000 for that. SO had I gone at different times I would not think it would be more than $1,000 one way or the other.
Comparing the two.
Commitment !! How committed are you to Florida vacations ? and your future. Both are great ways to take a holiday.
DVC is for the next 42 years, a home is yours ( or your families for ever).
DVC gives you (MAYBE if you are REALLY miserly with your points) 25-30 nights accomodation a year, a home ???? once it is paid for the only limit is your immigration limitations.
Cost DVC is an outlay of maybe 3 holiday costs AT ONE TIME and minimal per year after that, a house is a major outlay and potentially a major on going one after that as well.
Last thought.
A house is a MAJOR commitment/investment and should not be taken on lightly, I'm happy with it because that's where I want to live eventually( certainly for 6 months of the year. I don't think I would take it on just as an investment.
DVC is a great way to prepay your vacations, particularly if you find you have a spare £10,000 fall into your pockets and ( like me) know you'll only blow it !!!.
IMHO DVC is a GREAT deal if your looking to go on holiday to Florida once every 2 years minimum and like GOOD class accomodation for at least some of the time your there. I'd happily recommend it to anyone who fits that catagory. With DVC I KNEW after the first visit and going over all the details in detail I had got an absolute bargain.
A house is a really large commitment and while there are MANY of us who would like the idea, it needs more than that and does require A LOT of thinking and planning. I spent 3 years mulling it over and two years since I took the plunge, I think I did the right thing I'm not 100% sure though.