I like that you used a standard set of criteria throughout your 2x2s, and your reasoning behind them (how you judged them to be the most important to college students).
I wish you had included the name and key feature(s) of the products in the 2x2s, as they would help readers understand their distinguishing features and perhaps why they were where they were on the chart.
What if you downsized your herb tank idea to be just a herb pod? The technology would be simpler and the price would be much lower if the device took about as much room as a desklamp and grew perhaps up to 3 to 5 different plants.
Also here’s a competitor you missed for your herb tank, it retails for $70:
This one isn’t covered, though, and the plants may suffer from low humidity.