Personally, I think it depends on how often you practice yoga. It is worthwhile to buy an expensive yoga suit if you practice regularly. You will sweat when it is hot, or have a difficult class like Ashtanga.

I think expensive yoga clothes have three functions besides looking good:

1) Protect joints and prevent muscle strain. Elastic yoga clothes, similar to knee pads and wrist pads, can play a role in cushioning joints. Yoga clothes can slow down the speed of joint displacement and prevent joint sprain when doing some large-scale movements such as splits.

2) Protect the skin. If you sweat when practicing yoga, the fabric of yoga clothes is very important. Expensive yoga clothes are breathable and can avoid acne and the like. Moreover, there are some poses in yoga that require the skin of the body to touch each other, such as the cicada crane pose, where the knees touch the upper arms. If the yoga clothes are not soft enough, they may wear out the skin.

3) Ensure efficient practice. The better the quality, the higher the price and the more comfortable it is to wear. When practicing yoga, you won't be bothered by clothing problems. For example, the coat is too tight to breathe, the pants are airtight and feel hot, or the clothes are not elastic enough, and the front is split and torn.