Why is there even a market for organ transplant? Simple! Due to the existence of demand & supply, organs especially kidney is being traded like commodities
Why is there a demand?
There are many people mostly from the developed nations with health problems & is closely associated with unhealthy lifestyle like less work out, over-eating, stress, living in polluted environment etc. Somehow, they do have the means to pay
Why is there supply?
On the other hand, many hardcore poor people from countries like India & Brasil especially, are willing to sell off one of their healthy kidney in order to make ends meet. What attracts these poor people is the high market price offered
Why is the market price high?
(1) Demand outstrips supply. Demand from 1st world country is on the rise & yet some places like North America & Europe impose a legal bans on its sales. So technically, supply falls
(2) Demand & supply curve is inelastic. People are ready to pay for the high price & yet a kidney patient may need to wait indefinitely for a suitable donor. Therefore say, an increase in its demand will cause organs like kidney to fetch a very high market price
Is the kidney donor in poor countries better off?
Not really. In most cases they only received halve of what is being promised as they need to pay commissions to those middlemen