Why is rhino horn so expensive?

Could you explain why rhino horn has become such a highly sought-after and exorbitantly priced commodity? What factors have contributed to its skyrocketing value in recent years? Are there any ethical or conservation concerns surrounding the trade of rhino horn, and if so, how can we address them to protect these endangered species? Additionally, are there any viable alternatives to rhino horn that could potentially alleviate the demand and help save these magnificent creatures from extinction?