The guy who has that business is a broker of other peoples' points. Sort of like taking your stuff to sell at ISoldItOnEbay, rather than just selling it yourself on ebay.
Plenty of people rent out their own points if they can't use them.
It's expensive, but we financed, and the monthly payment is very doable for us. And once we get our car paid off (August, baby, 2 years early!) we'll get DVC paid off in short order as well. We figured that we were working to save more than the monthly payment to pay for our hotels at DLR anyway. And to think of saving for WDW was really hard! But once we bought in, "saving" (aka paying the monthly payment) hasn't been hard at all. And in about 1.5 years when we're done with the payments, assuming we don't buy more, LOL, we won't have to pay on accomodations at all.
Of course the maintenance fees are what'll get you.

But probably not as much as rising hotel costs.
We had our first meeting with our guide in '07. Didn't buy in, didn't think we could afford it. Then in '09 we did it, because even though our income hadn't changed much, our outgo had. Then right after the recision period ended, DH got news of a layoff. Somehow, having that debt caused us to rise above the problems...DH did get a job that he started almost immediately after his department closed, but instead of blowing severance and signing bonus, we put it towards debt. The DVC pushed us into being "better" than we had ever been before, and our lives have changed a millionfold for the better, and I'm not sure it would have happened if we hadn't bought in.
But I digress.
We know we're going to DLR, and we knew we were going to WDW. We have family in both areas. So we figured we'd rather put out x dollars to buy in, and pay the maintenance fees, and have the ability to stay in places other than the value resorts (though we're likely adding 2 nights at a moderate on at the beginning of our big WDW trip, and we would gladly stay at a value if we felt like it!) when we visit WDW.
I will also state that I did NOT buy at the Grand, because I'm not the biggest fan of that hotel, and wanted to "leave" the points for those who do love it. So we're just nutty....west coast, go to DLR a lot, hadn't/haven't yet been to WDW, but bought in at a WDW resort.