Probably it only makes sense to make your own tracker if your main interest is designing and building tracking systems yourself. If you just want to have a tracker then it is much simpler and less expensive to buy a tracker.
Cameras is a very small part of a tracking system. You need to have a lot of additional hardware (a solid frame that can hold the cameras in place, with strong mounting point(s), built-in ring lighting, memory to store calibration data, power supply, communication interface to the computer, etc. all in a compact enclosure) and software (for calibration, marker tracking, 3D pose computation with filtering, automatic camera control, interfacing with drivers and operating system). While you can use off-the-shelf components and open-source libraries (e.g., calibrate cameras using OpenCV, detect/track markers using ArUco), you need to still spend a lot on buying all the hardware pieces and develop and maintain the software.
You can get accurate, convenient, integrated, factory-calibrated optical trackers with built-in infrared lighting and tracking software at very affordable price. For example, an OptiTrack Duo costs just $3000.
Note that setting up a system of multiple cameras is more complicated and more expensive than getting a Duo. You need to buy a calibration tool, power supply, networking equipment, buy license, etc. With the Duo the setup is really easy, you just plug it in, and it works (it is recalibrated and perpetual license key is a included).