There are a few reasons as to why you would want to do a complete teardown: if you are inexperienced then this will give you a better idea of the parts inside your device, you limit the amount of cutting-corners you'd have to do and most likely damage something, and well, knowledge is power, right?
I would say that if you are taking on the task of repair yourself, it is worth it in spades! Not only do you get experience, gain confidence in taking apart electronics, and learn about your device, you are also limiting your e-waste footprint and 'leveling up' your repertoire.
I've always been on the low-end of the economic scale so I undertook repair as my only option, even though it was foreign to me and kinda scary. The fear of the unknown and the doubt in my abilities were by far more detrimental than my actual lack of experience. I've repaired cars, motorcycles, home appliances, consumer appliances and much more, strictly out of necessity. I feel that the skills I have gained from these various tasks I have earned with the good ol' blood/sweat/tears cocktail. Repair has changed who I am and how I view the world, and helped me to appreciate my (albeit very tiny) place in it. Repair is freedom but it is also responsibility. Repair makes you a more complete person I feel, and less of a blind consumer running after shiny new beeping trinkets. My purchases are informed by my experience, and I feel that I get more out of my devices.
Apologies for the rant but repair is a passion of mine, and I believe it should be shared as much as possible. So, yes, it is worth repairing for more than the fact that you fix something broken--you grow as well. This may be a low-cost item now but it wasn't necessarily when it came out. If you upgrade in the future and need to repair something not so low-cost, you will have more confidence in your skills and yourself. Good luck!