Black Friday deals are often a mixed bag. You might save some cash up front, but often the best deals are for products of lower quality that you end up regretting later.
But if you have the chance to snag a cheap Blu-ray player, I'd say go for it. I've reviewed a bunch of midprice Blu-ray players this year, which typically add premium features such as built-in Wi-Fi and "Smart TV" streaming service like Netflix, Amazon Instant, and Hulu Plus. Though they're nice perks to have built into the player, the reality is that the "Smart TV" features on even the best Blu-ray players are still relatively limited and clunky.
The alternative is buying a cheap Blu-ray player without premium features and adding a $50 Roku LT. The Roku gets you the built-in Wi-Fi access you want, plus offers hundreds more streaming services than any Blu-ray player on the market. Roku also updates its boxes several times a year with new features (like cross-platform search) and services, whereas Blu-ray players are typically abandoned once new models are announced in January at CES.
And don't worry that a cheap Blu-ray player will produce inferior image quality. I've tested dozens of Blu-ray players for CNET, and during the last couple years all of the major manufacturers (Panasonic, LG, Sony, and Samsung) produce nearly identical image quality on Blu-ray movies. Even the differences on DVD playback are now so minor that only the pickiest videophiles will care. And while there are some differences in disc-loading speeds among models, they're not large enough to consider when making a buying decision. (You're taking more of a gamble with image quality and disc-loading speeds if you go with a bargain brand like Dynex or Magnavox; I haven't tested those brands.)
So if you see a bare-bones Blu-ray player like the LG BP220 selling for an unbeatable price on Black Friday, you can fearlessly add it to your shopping cart. By adding a Roku LT later, you may actually end up with a better combination than if you had purchased an expensive player in the first place.