Amazon has the Samsung UE510 28-inch 4K LED Monitor on sale today for just $229. This is for the certified refurbished model that is typically priced at $299. So that's good for $70 off of its regular price, and that's definitely a great price for this monitor. The original price of a new model is well over $400, so this is a great time to pick up a 4K monitor, in Amazon's Gold Box Deal of the Day, today.
The Samsung UE510 is a 4K monitor, that is about 28-inches (measured diagonally). Now that's not the biggest monitor out there, but it is a pretty decent size. The 27-inch monitors are the most popular models out there, so getting an extra inch is definitely nice - and it does make a difference. This is a 4K LED monitor, so you're not going to get that crazy good picture you would from an OLED display here, but it is in 4K which is going to be really nice. There is AMD's FreeSync which makes it great for playing games on the UE510. Now this is a certified refurbished model, which Amazon lists as coming with all of its original accessories, as well as a 90-day warranty from Samsung as well as its regular warranty here. So you'll be covered if anything goes wrong with the UE510.
This item is also eligible for Amazon Prime's free shipping. Which includes free two-day shipping, and pretty cheap (usually $3.99) next-day shipping if you need it extra fast. If you are not an Amazon Prime member yet, you can sign up for a free trial of Amazon Prime. You'll get 30 days free (if you're a student, you get 6 months), and then it's $99/year (or $49/year for students). Prime members do get a whole lot more than just free shipping though, so be sure to check out the full benefits.