The cremation it's self is £75 (our three local boroughs waive it for childrens funerals).You're paying for the coffin, cars, pall bearers, flowers, collection and storage of the body, embalming, make up, staff costs (leave, pensions, sick pay), the celebrant/vicar/priest, collection of the ashes, the casket
Sorry, but rubbish. A direct cremation costs over a thousand pounds. No cars, no pall bearers, no flowers. No funeral. That's literally just to have all the legalities done, a cremation and have the ashes delivered back to you in a box. I've just paid for one, so yes I know
But if you want to put your dearly beloved in a cardboard box, pop it in the back of your hatchback and lug them into the crem, then no one would stop you
They would stop you. The hospital/mortuary wouldn't release the body to you and the crematorium, oddly enough, will not cremate dead bodies that people take out of the boot of their car, no questions asked. 