Would a battlecruiser museum ship cost about the same to run as a battleship museum?
Short answerProbably slightly more, because the larger and more lightly protected structure can create additional maintenance demands.
NotesLighter armour does not necessarily make a battlecruiser a cheaper museum. The hull may be larger than that of a comparable battleship while relying on thinner structure in some areas. More exposed surface and different structural needs can complicate long-term preservation. Operating and maintenance costs could therefore be slightly higher rather than lower.