Yes, many members buy both direct and resale because they want the direct points for different reasons (e.g., blue card, ease of purchase, speed of receipt of points), but they don't want to pay direct prices for all of their points. For example, if you know that you want to purchase 250 points in the next year and you want the blue card for the annual pass discounts. you can buy 150 resale points and 100 direct points for the same resort and use year.
You'll hear often that you want to buy resale first and then direct because if Disney has the points, they can match whatever use year you want. Wit- resale, you're subject to whatever is available. For example, let's say you find a great 150 point resale contract for your desired resort and it has a March use year. You can buy it and also call Disney and say you want 100 points at that resort and if they have them, they will match the March use year. However, if you buy direct first, and you choose a December use year, you may wait and wait and wait for a 150 point resale contact with the December use year.
Friends, please correct me if I'm wrong. This is only my second post, but I've been reading these forums for so long, I feel like I know what I'm taking about, LOL.