Where did you find that deal? I've been tempted to get something similar many times. Pen or watch or lighter. I'd probably gamble and get one for myself at that price. I can think of many uses, provided it's easy to erase or loop the audio and video, and can use a large capacity micro sd card. Often those sort of things are limited to maybe 8 gb max.
Ah.... reminds me of my days as a stealth photographer / videographer.
I used to "do" video surveillance/mystery shopping. I wore a shirt, where a button was a lens, and a cam recorder under my shirt good for about an hour.
Many companies used out services to check out their stores and sales people. Usually pricier items.
One company I was contracted with did integrity shops for a major mobile home builder. It was my "job" to tour and than strike a deal for a home I liked. Along the way, I would "try" to commit fraud by having them "increase" the sale price so I would not have to pay a down payment, thus conserving my cash for furnishing, etc.
Since the manufacturer used HUD, IF caught committing that type of financial/mortgage fraud, the dealership and manufacturer would be fined 1 million dollars. So all their dealerships were checked in this method once or twice per year.
The job entailed a tremendous amount of travel. One trip, after flying from Florida to Seattle, I put over 6K miles on my rental car in about 3-4 weeks, all the way to Kansas and back. Visited and purchased at over 50 dealerships. Also got to stop at well over 100+ casino's.
It's been 10+ years now, and I really had a blast while it lasted. Several hundred new car dealerships, housing & condo projects, other retail chains. Pawn shops. Mattress stores. And the really fun "fraud" mobile home shops.
The videos were a tremendous aid to evaluate sale people. Their team could actually watch their people in action, and hear both sides of the conversations. These were very expensive compared to "normal" mystery shopping where the secret shopper wrote their recollections, and the merchant had to rely on their memory and accuracy. With the videos, the "proof" was there for all to see.
I'd do that again, but the company is out of business. Prices started in the range of $500 per location.
Even got to video shop 11 casinos! Got paid $150 per for those, plus reimbursed up to $150 on any losses. Several times I did a weekend, and got 3 shifts, stayed overnight, got three more shifts, made a guaranteed $450/day, plus "if I lost", got reimbursed up to $150 per shift. I remember losing 3 shifts that weekend, and winning almost 3K. Got reimbursed the $450, plus shift pay per video, and expenses, and came home with $4K for my work.
There was a script to follow, so to speak, and I needed to interact with at least 2 dealers, plus pit bosses, slot/change person, and CW's. Oh, did I mention there was also a meal? Gosh, what a great gig that was! And I was the only person with the company that had casino experience.
Fun memories of a great "job" for me.