resale buyers currently get the same dining/shopping discounts as direct buyers. those dining/shopping discounts can go away at any time for both direct and resale buyers. (it's going to take a lot of 10% off discounts to add up to the thousands saved by buying resale either way.)
the only big difference currently between direct and resale is access to trades for disney cruises and disney hotels (also "adventures by disney" - but those take HUGE numbers of pts). the cost of trading out for cruises and such is usually more expensive than simply paying cash (renting pts for
DVC stays and using the cash).
resale buyers get the same member perks otherwise, including access to trades for RCI and intrawest timeshares. and if your circumstances change and you need to sell your DVC contract, you will be selling at resale prices even if you paid extra to buy direct.