I’d be thinking Epcot area like already mentioned.
Swan/Dolphin package through Costco would be high on my list of places to check when looking at prices, OR, figuring out Priceline to narrow the Resort down to Swan/Dolphin if you’re feelin lucky.
Bonus Answer for the Bonus Question:
The Swan/Dolphin restaurants are generally always in the conversation of “Best Of” on property.
Kimonos for sushi (and drunken Karaoke) might be great call if you dig sushi. There’s no chance I’d go for more than 2 days and not go to Kimonos. Bluezoo, Shula’s, and Il Mulino are pretty highly regarded. World Showcase is a quick 10 minute walk, and the Boardwalk is at Swolphin’s back door, over the bridge. Some might say that Swolphin restaurants are better because they are not Disney run.
All of the EP resorts are connected by a walking path - very quick walk between them all. If one is glaringly cheaper than another, you gotta check what’s most important. Swolphin won’t let you have Magical Express or any Dining Plan, but for our needs, that doesn’t matter in the slightest.