Definitely only go with a resale. I use sell timeshare for Fairfield (Wyndham ) resorts and points are not a good idea for the buyer. There is no real benefit to you, just to the resort. Also, don't depend on a trade with RCI. If you own Aruba you can go almost anywhere else, but don't expect to get back into Aruba with another timeshare in high season.
As for why to own a timeshare? No matter how much you pay to a hotel, its still 'rent'. You can't get one penny of it back. If you buy a timeshare and after 10 years decide you don't want it anymore, you can get most of what you paid when you sell.
Also, when doing your calculations for $400 a night for 7 nights for 10 years, you didn't take into consideration that the price of the hotel room will continue to rise. Maintenance fees never go up at the same rate as hotel rates.
As for the price you quoted and $1000 for maintenance, you must be looking at the Marriott and there are much better opportunites for timeshare ownership in ARuba that won't cost you nearly as much.
Figure out what size unit you need and if you need help, let me know.
macalh@aol.com