I just checked out the product on HH's website. It's not really the type plasma light that many people probably think of. IOW, it's not a sulfur plasma light. Those have bulbs that are golf-ball sized or smaller, have a magnetron, and tend to produce staggering amounts of light.
This is "the other" style. It's a magnetic-induction electrodeless
fluorescent lamp. I don't believe it's considered to be a plasma induction lamp (although I could be mistaken).
They do look to be pretty efficient for a fluro. The bulb should last far longer than the traditional fluorescent bulbs and you won't see the degradation that makes the ends of tube-style bulbs go dark. I have recently read that induction fluorescents with separate ballasts can last up to 100,000 hours and that ones with integrated ballasts can last 15,000-50,000 hours (with models containing cheaper Chinese-manufactured components generally falling at - or below - this range). Depending on the spectral profile of the bulb's output, they might make excellent supplemental lighting. Or, if you purchase enough of them possibly decent enough on their own (but I'd look for something in the 300-400 watt range (efficiency of lights of this nature tend to tank above 400 watts) if you were looking to use induction fluorescents by themselves).
Well-built models are said to use cleaner components that do not produce birdies throughout the RF spectrum, while cheaper models can be a crapshoot. If you purchase (or already have) one or more lights of this nature, you might want to use an EFI/RMI filter on the power line and use a "police" scanner (on a separate circuit) to do a search from 25mHz-1.3gHz or so in order to make sure that the device isn't producing any (substantial) radio interference. The unit probably operates on 2.65mHz (or ~2.45mHz) although other popular operating frequencies include 250kHz and 13.6mHz. But due to resonance and other RF properties, it is possible to "see" interference caused by a device at frequencies other than those the device uses. I would run a scan/search whether you can find "China" stamped on the device (or any of its components) or not. While it's extremely unlikely that you'd run into a LEO who is driving the streets of his/her jurisdiction with a scanner or RF detection device - or even that it would, for example, cause interference with a neighbor's WiFi, lol - it'd still be nice to know if the device is outputting RFI and if so at what frequencies and how strongly.
For $150, that device seems to be a little steep for its output (listed at 3900+ lumen) - but then again, so are LEDs, lol. But a $59 Sun Systems 150-watt HPS growlight fixture (comes with bulb) produces 16,000 lumen. I'm willing to concede that this device's spectral output might be closer to what the plants utilize - and therefore might be appreciably stronger than its lumen rating would lead you to believe - but still, the differences in ratings are so great that I'd expect the SS HPS to produce more/better/faster. However, if you are restricted to a maximum monthly (lighting) electrical budget of 50 watts or less then this device (or one of its nature) might be the best for you. And if you just like trying "new" (technology has been around for a
LONG time) things/technologies then it might well be worth $150. They really do seem to produce a decent output for their "size" (electrical usage).
EDIT: Here is a (Wiki) page that briefly describes both plasma and magnetic induction lamps for anyone who is wondering about either:
Electrodeless lamp - Wikipedia