The sensor that could save (plant) lives
For example, Koubachi’s Wi-Fi plant sensor , falls into the category of useful (ish) but way too expensive to justify buying.
The sensor, which you stick into the soil of your household plants, tracks moisture, temperature, and light and sends the information over to Koubachi Plant Care Engine on your computer. The system provides you with detailed instructions on what you’re doing terribly wrong with your plant-child and how you’re ruining its life. It will judge, I mean, notify you if the plant needs watering, temperature adjustment, positioning adjustment, fertilizing, or misting. It's fairly versitile, you can use it in almost any type of soil and with any plant. After one week, you can remove the sensor and the program will give you directions based on the information it gathered during the week.
At first, I was almost swayed by this seductive technology. I’ve proven to be a fairly chronic plant killer in my day, and I like toys.
But then I saw the price tag: $99.
Do you know how many plants I’d have to kill to justify that purchase? 66 wave petunias  at $1.50 each, 176 individual gerbera daisies  at 4.50 for $8, 31 cantaloupe jumbo plants at $3.10 or 13.2 rose plants at $7.50.
I spent enough summers working in the garden department at a large not-to-be-named box store to know that is A LOT of flowery death. At that point, it’s probably time to find a new hobby.
Unless you’re growing a one-of-a-kind Corpse Flower a la Dennis the Menace , a normal person doesn’t need this sensor. It's a useless technology cleverly disguised as something you need. A key component of buying tech and toys is considering if the price justifies the means. For example, do I need a $1500 MacBook Air? Personally, I use it for work, so I can justify the cost and I trust Apple to design a decent computer. But spending $99 on a sensor when I could really just use my thumb to check for moisture and google the information about the plant that the sensor provides, seems like a giant waste of money (that I could spend on Apple products.)
Part of the fun of gardening—or so I’m told by my green-thumbed friends—is that it’s not an exact science. It’s about cultivating the plant and learning along the way. It’s not fun if you have a day by day log of how to care for this specific plant in this specific temperature in this light.
Mostly, it’s too expensive.