This has been coming up in more comments than we expected, so we'll make it easy for you here: The Dell Venue 8 7840 tablet — it's not official unless you use all of those numbers, in the correct order — costs $399. That's for the one and only model currently available, with a mere 16GB of on-board storage (with about half of that available to you after boot).
If you purchase from Dell, you'll see a few "deals" that include a folio case, Dell Cast dongle or wireless keyboard and case. But the tablet model remains the same.
Be sure to also check out the first five things you need to know about the Dell Venue 8 7000 series!