'Direct to Crematorium' funerals are becoming increasingly popular. They cost around £900 - £1200 depending on where you live.
It is extremely basic with the undertaker collecting the body, putting it in the cheapest possible coffin (possibly cardboard) and taking it to the crematorium, usually in the undertakers' van, not the hearse. The body can't be viewed, there is no service.
David Bowie opted for this. Of course the family can have a service, a ceremony, a memorial or a jolly old knees up at a convenient time wherever they want it.