Microsoft didn't have much luck with the MS Surface tablet when it launched in late 2012. Originally a $500 tablet, it has been marked down again and again, finally ending up with a $300 price tag (its replacement costs $449). Microsoft even ended up taking a $900 million charge in July 2013 due to unsold inventory, but their loss is your gain.
Today you can get the original Surface RT tablet as a refurb. A reader (Thanks, Patrick!) tipped me to the fact that it's selling on Ebay for $169, making it potentially a good deal for a budget tablet.
Update: The seller bumped the price to $199.
This 10" tablet runs Windows RT 8.1 on a quad-core Tegra 3 CPU with 2GB RAM, 32GB storage (only about half is accessible), a microSD card slot, 2 cameras, and BT/Wifi. Screen resolution is a decent 1366 x 768.
The Surface RT was originally conceived as a competitor to the iPad, but now that you can get it for $170 it is arguably worth considering as a budget tablet. The specs alone make it a good deal at $169, though this is a refurb so you might want to also buy a warranty. The screen size, CPU speed, and storage is better than what you can find for large tablets in this price range (unless you're looking at another refurb).
But the OS, well that's another matter. This tablet runs Windows RT, which is the cut-down version of Windows 8. You can run Windows RT apps but not anything developed for an earlier version of Windows, and that limits what you can do with the tablet. You're stuck with whatever apps have been developed for this particular OS, and if they have quirks or simply don't work then tough gummy bears. For example, the Kindle app for Windows 8/RT cannot read ebooks that are downloaded from sites other than Amazon. (I think it has to do with this app being the functional equivalent of the Kindle Cloud Reader, but I'm not sure.)
And then there's the baffling interface. I don't know anyone who likes the Metro interface on Windows RT/8, and after reading Jane Litte's review of the Surface Pro 2 I'm pretty sure I'll hate it as well.
But on the plus side, a couple readers reminded me that this tablet does come with Office RT, which is a more complete version of an office suite than can be found on Android (Thanks, Lynne and Paul!).
And in case you were wondering, it's not possible to install Android (I checked).
But it's not like the Surface RT is completely with out apps; there are web browsers, the Nook app, and there was also the Kobo app (before they pulled it), and even Adobe has released a version of Adobe Reader.
So as a $169 budget tablet, this is not a bad deal. But it's also not necessarily the absolute best deal.
For about $80 more you can get an 8" tablet which runs a full Windows 8 (and not Windows RT) MS is selling the Toshiba Encore for $249. And if that's not your thing then you could get the Dell Venue 8 for $265 (at Amazon). Sure, those tablets cost more but are also a heck of a lot more capable than the original Surface RT.
But if you're as cost-conscious as I am then you'll probably spring for the Surface tablet refurb, which is still a not a bad deal.
P.S. Or, and just to give you a left field suggestion, you could get the Nook HD+ for $179. I didn't much care for the quirks B&N introduced but the screen quality and battery life were impressive.