I work in the funeral industry and depends how you are looking at costs.
Though about it funeral homes have staff on call 24/7, 365 they usually aren't expensive salaries but you need a few people to manage that if.you think about rotas/ time off.
Then you need bearers to help during the funeral and the actual funeral director preferably not the people that have been up all night so there's more employees.
Then you need people running the actual funeral homes and caring for the deceased, so more employees.
You also want good well trained staff who know all the legislation that applies to funerals so not only are you going to pay for the training but they need time off to do that.
Then you have the cost of premises, insurance all the usual overheads a business has.
Coffins are made to a very particular standard so the costs of them are reflective of that.
Hearses and Limousines aren't just bought from car manufacturers they are built by specialists (there's not a big enough market for the car manufacturers to be interested) they aren't just thrown together it takes a huge amount of work and specialist knowledge which isn't cheap, so they cost between £100-250,000+ new so there's those costs to offset and obviously they don't want them breaking down they are replaced every 4-10 years.
Then there's the costs funeral directors have no control over like how much the church, crematorium or the council charge for a burial or cremation.
You can already see from my list were the costs all add up. Also just like any other business they should be allowed to make money, there's very few industries were you are expected to arrange the equivalent of a wedding within a few weeks without making any profit at all.