I'm interested in acquiring a cruising houseboat. Recently I came
across what looks like a good opportunity:

DE GROUT 36 Shotblasted, empty shell, faired and painted. Windows and
deck hatches fitted. Davits, ladder and diving platform. All ready to
be fitted out. Year: 2000.

My question is: realistically, how much could it cost to finish it and
turn it into a cruising houseboat (in the UK)? I'd just like a rough
estimation to get an idea if it's worth looking further or not.