Here's my thoughts, and hopefully I'll be able to swing this back around to be design centric rather than shopping centric.
The whole USB thing really isn't interesting. It uses USB for power only, so basically USB is an over-glorified wall-wart. Having the ability to power it off of a computer isn't a huge benefit compared to the voltage and current limitations it gives.
The voltage regulator is a linear regulator with a pot for adjusting the Vout. Any halfway competent hobbyist could hack something together in 30 minutes. 10 minutes for someone that is experienced. They would also likely use a better heat-sink to the max power is higher. And using some leftover wall-warts from "the box of orphaned wall-warts" makes this super cheap. If you hacked something together using spare parts lying around then you might spend US$5 and it would work just as good.
The 7-segment display is a waste. It is useful, sure, but there is so much more that could have been achieved with that micro-controller.
Here's how I would have designed that device to be much more useful:
Use a micro-controller with an actual USB interface. Using a small app on the PC you could control the output voltage and monitor the output voltage and output current. It could implement some sort of programmable overvoltage/current protection as well. Controlling multiple vout's with sequencing or other simple "waveform generation" could be very useful.
The power supply itself would be a switching regulator based on a SEPIC topology. This way the output could be either a higher or lower voltage than the input. The output voltage/current is controlled from the micro-controller. It is actually fairly easy to control the output voltage. Output current is a little more difficult, but not impossible.
If a low-noise output is required then I would follow the SEPIC regulator with a programmable LDO regulator. Again, the output voltage would be controlled by the micro-controller. Usually the LCD output would be about 0.5v lower than the output of the SEPIC. In this way efficiency is still mostly high, but the output noise would be very low.
Then I would design a similar device, but instead of a programmable supply it would be a programmable load. USB controlled.