While Microsoft's formal response to the Chromebook threat will result in a number of inexpensive new PCs this holiday season, you don't have to wait if you're curious about the low-end of the PC market. There are already a number of PCs available for under $300 if you're looking for the familiarity and power of Windows.

Of course, there's a big difference between today's $300 PCs and the devices we'll see later in the year. The coming range of new PC designs are designed to compete head-to-head with Chromebook, so they'll feature very similar thin and light designs with 2 GB of RAM and low-capacity but fast solid-state storage. Check out So What Does a $200 PC Look Like? for an example.

Today's inexpensive PCs are generally bigger and heavier, and weigh almost 5 pounds. They generally feature 15-inch screens, Celeron/Bay Trail processors, 4 GB of RAM, and high capacity but slow traditional hard drives, typically 5400 RPM units with 512 GB of storage. Those specs won't deliver stellar performance—the hard drive will hurt most—but then they don't have to, given the market.

These machines cost under $300 at Amazon, which is about the same price as the average Chromebook, so we can remove that issue from equation. Instead, the choice boils down to the now-standard tradeoffs between Windows PCs and the typical Chromebook: Power vs. simplicity, full offline use vs. limited offline use, full peripheral compatibility vs. not-terrible compatibility for commonly used peripherals, real Office and iTunes vs. web-based alternatives, middling battery life vs. strong battery life, and so on. You know the drill.   

I've been meaning to evaluate a sub-$300 Windows laptop to determine how well these devices work in the real world. But an email from Amazon—always eager to sell me something else, of course—reminded me about this ongoing battle.

Apparently, I've expressed an interest in PCs

The online retailer is advertising four sub-$300 Windows PCs, each of which is not-surprisingly very similar: Dell Inspiron i3531-1200BK 15.6-Inch Laptop ($250), Toshiba Satellite C55-B5298 15.6-Inch Laptop ($230), ASUS 15.6-Inch HD Dual-Core 2.16GHz Laptop, 500GB (plus a version with an optical drive at no additional cost, both at $273), and Acer Aspire ES1-511-C59V 15.6-Inch Laptop ($250).

None of these machines are particularly inspiring, of course. But for the price, you're getting full Windows and all the potential—good and bad—that that brings to the table. And they are available right now.

Looking ahead to the fall, we see two interesting trends.

First, as noted, PC makers will be delivering Chromebook designs running Windows, and we'll see a variety of thin and light models with 11.6-, 13- and even 14-inch screens. These machines will cost even less than today's low-end PCs, with prices starting at just $200.

On the Chromebook side, we see that platform evolving in the opposite direction: More powerful processors, including familiar Intel x86 "Haswell" processors, and more devices with larger 13- and 14-inch screens; most of today's Chromebooks are still netbook-esque 11.6-inch units. And, sure enough, prices are creeping up: Those bigger devices with better screens can cost $400.

In order to evaluate the changes on the Chromebook side, I've preordered an Acer Chromebook 13 CB5-311-T1UU from Amazon that I believe is shipping in early September. This doesn't have a Haswell processor, but its NVIDIA Tegra K1 Quad Core processor is allegedly even better, and the rest of the specs are high-end (for a Chromebook) and thus semi-future-proof (for Chrome OS): 4 GB of RAM, 32 GB of internal storage, a 1080p 13-inch screen, and 11 hours of battery life. But it costs accordingly, too: $380.

But I'm wondering what to do on the Windows side.

I could go with one of the $300 PCs noted above—I'm leaning towards the Dell for some reason, but I don't think it much matters—or wait to see what happens come the holiday season. Or I could do both, I guess. These machines are relatively cheap, after all.

So what would you do, if forced to limit your spending in this way? You've got $300 to spend on a new PC. Do you bite now or wait?