How much does it cost to retrofit a twenty three passenger van with a wheelchair ramp?

Check on EBay for a Hydraulic Tail lift and ask local garage about fitting.

I sold the Hydraulic Tail lift off my old Welfare Ambulance for £75.

The reason for removing was that I am converting to a Campervan.

Be carful though. The Hydraulic Tail lift unit is VERY HEAVY!

Hope this helps