Why do people complain about this stuff? They’re not a necessity. No-one’s life was ruined because they didn’t have a replica kit, though granted some people can get quite upset if they’re unable to express their individuality by dressing the same as everyone else they know.
Companies charge this much because people will pay it. If you think the cost is excessive then don’t buy it, and eventually the people getting filthy rich out of selling them will realise that if they want to continue making money, they need to charge a more reasonable price.