There is no correct answer for everyone. Direct is NOT cheap; resale can be either as little as a $1 or 50% of developer prices.
You have to ask more important questions as to your family size and ages, where you live now, what you like to do on vacation, how many vacations a year, expected level of service, time of year, etc. Some people NEVER want to go back to any resort twice; others have to be pryed away from the only place they have ever gone.
Just remember, it is far easier to buy a timeshare than it is to sell one (or give it away or deed it back or any other means to get it out of your name and off your credit report).
Good Luck.