How long would you say that 2-3 mm front brakes should last?

Under normal braking conditions they should last about 5,000 miles. here is how you can replace the front brake yourself and save some money. The pads will cost $30.00 link below.

https://amzn.to/3KI1drO

Also here is a guide to help you raise the car and remove the wheels. Go over the guides before you begin.

https://www.2carpros.com/articles/wheel-removal-and-re-installation

and

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.