Get a pair of Harman Kardon in-ear headphones for $18.99

Harman Kardon is a high-end audio brand, so when you see what appears to be a smokin' deal on one of their products, you can't help but take notice.

And here's what I noticed: For a limited time, and while supplies last, the company is offering its own Harman Kardon NI in-ear headphones for $18.99 shipped when you apply coupon code HKNIDEAL at checkout. These list for $99, sell direct for $73.99, and can often be found on sale elsewhere for around $40.

Let me note right up front: The user reviews on these could best be described as "mixed." But let me come back to that.

The NIs are noise-isolating earphones that come with three sets of silicone sleeves (small, medium, large) and a carrying case. They also have an inline microphone with remote controls. However, only iPhone and iPad users will be able to fully take advantage of those controls; most Android devices can't leverage the volume buttons, which is no fault of Harman Kardon's.

But I suspect a lot of Android users don't know this, which explains at least some of the lower ratings. On both Harman Kardon's product page and Amazon's, you also hear from some users who don't seem to understand how in-ear headphones work (i.e., they're not buds that just rest inside your ears, they're earphones that must be inserted to form a seal).

And don't overlook the occasional nutjob: One reviewer actually gave the product two stars because his car was broken into and the thief stole his headphones! (That was after noting that they "sounded phenomenal.")

All this is not to defend the NIs, just to note that when it comes to certain products -- headphones in particular -- quality can be very subjective. I've repeatedly purchased those $10-12 Marley in-ear 'phones from Daily Steals, and to me they sound great. Hard-core audiophiles would likely say otherwise.

Ultimately, this is a chance to score a high-end, name-brand set of earphones at an impulse-buy price. Curious to hear your thoughts on whether it's a deal worth doing.

Bonus deal: Speaking of deals that may or may not be worth doing, I've repeatedly dinged Microsoft for charging way too much for Windows. But expiring today, Software Supply Source has Windows 8.1 Professional (Full) for $64.99. Microsoft charges $199.99, which is ridiculous. I haven't found any red flags, though I do think you should avoid this unless you know how to upgrade/install Windows. In any case, this is a lot closer to what I consider a reasonable price for Windows ($40 or less).