You can leave your body to be used for medical students to practice surgery techniques on. If you do this it costs you/your family nothing and the medical school will collect the body and do all the paper work.
Other than this it is 100% legal to put the body in a body bag and have it delivered direct to the back door of a crematorium and put straight into the furnace with no ceremony at all.
This should cost around £400. You have to pay for the death certificate and the clearance for cremation , approx £85. Then the body bag from £20 on eBay ,transport to the crem, this can be the back of a van or estate car it DOES NOT have to be a hearse , cost free or what ever it costs say £20?
The main cost is the cremation fee of around £300.
Get someone on benefit or pension to apply for a funer