Hi Diana,
There are all kinds of amazing suites available across Walt Disney World but I'm not sure I would call them "cost effective." You can easily search for options in suites on
Disneyworld.com. On the home page, click on "
Places To Stay." Once on that page there are several drop-down menus. If you click on "Resort Characteristics" you will be able to check boxes for "Suites and Villas" and/or "Club Level and Suites."
If cost is an issue, one of Disney's Deluxe Villa Resorts might be a great option for your family. Many of Disney's Deluxe Villa Resorts have two-bedroom villas that sleep 8 or 9. The villas also have a kitchen and living room which gives you a bit more room to spread out. I love
Bay Lake Tower at Disney's Contemporary Resort or
Disney's Old Key West Resort.
You also have the option of booking two rooms at any of the resorts. You could request connecting or adjoining rooms but they are not guaranteed.
As you continue to plan, please let me know if I can help you further with this or any other question you might have!
Wishing you happy planning and a magical vacation,
Amy H