Well, first off, yes, it is expensive for a box cutter. The cheapest Home Depot has to offer is a little over $2, and $15 buys you a branded utility knife. So, at €39 (approximately $43), the Maker Knife v1.1 is indeed pricey.
But it's well made. Incredibly so. I've got a stack of cheap box cutters, and they're little more than handles for utility blades. And they have plenty of flaws. The handles are bulky. The blades are poorly retained. Swapping blades is a pain. The thumb button for the blade is usually huge and catches on stuff.
The Maker Knife v1.1 is a precision-made bit of kit. The build is sleek and lightweight, which is handy when you want to do some precision cutting. This is exactly what I'll be using mine for, not heavy duty hacking and chopping.
The Maker Knife v1.1
The locking mechanism is also smooth as butter, and does what it's supposed to do -- keeps the blade retracted when you want it retracted, and keeps it locked out when in use. You can even tune the knife to suit your personal taste -- there's a screwdriver and instructions included to help you.
The latching mechanism, which is operated with a finger, is smooth, and a wonder of engineering.
Since the locking mechanism is a safety feature, I appreciate that it's well-made and does what it's supposed to do.
The Maker Knife v1.1 also has one of the nicest pocket clips I've come across on a knife. It's deep, and holds the knife in place securely, and yet doesn't make the knife uncomfortable to use. Everything is polished and smooth, and a pleasure to use.
If you're happy to pay for a decent tool, the Maker Knife v1.1 won't disappoint. I like mine a lot. If you'd rather buy something for a couple of bucks, the choice is yours. No one is forcing you to spend more than you want.