True, it all depends on how well they emulated the design of the Soltek lights. However, I would wager to guess that even if it was a poor duplication, they will still outperform the other Chinese made aux lights (PHIDS) that everyone raves about.
$100 is practically giving them away. A replacement HID bulb could range anywhere from $40 (D2S) to $100 (D1S) depending on the type they use. Then add the cost of a ballast, and the light is fairly reasonable. Not to mention the fact that SolTek's cost on average $300 per lamp, PHID's originally sold over over $600 a set, FF200 are over $500 a set, and even the Hella Micro DE Xenon driving lights are still over $500 a set. I think in the grand scheme of things $200 for a set of HID lamps is very well priced!
I wouldn't recommend using these lights as driving lights on the freeway. By the time you dip them down low enough where you are not blinding oncoming traffic, they're not going to be casting alot of light down the road. If you want HID aux lights that you can have on with oncoming traffic, I think your best bet would be to look for aux lights designed for that. Ones that come to mind are the Hella DE Xenon lights. Not cheap by any means, but they have a cutoff and are designed as fog/driving lights.