The cost of the best stereo speaker in India can vary widely depending on the brand, model, and features. High-end speakers from well-known brands can cost upwards of several lakhs of rupees, while mid-range models can cost anywhere from a few thousand to tens of thousands of rupees. However, it's worth noting that the "best" speaker for one person may not be the same for another, as individual preferences and needs can differ. It's important to do research and listen to different speakers before making a purchase to find the best fit for your needs and budget.