For the bid itself, estimate the condition work separately and deduct it from the value you would assign to a comparable usable warehouse. Don’t just copy the largest observed discount; it may reflect defects that the target property does not share.
I wouldn’t conclude that renting automatically wins just because five to seven years sounds short. Your rent can change too, and ownership gives you more control over the apartment. But I would not use “I can always rent it out” as the escape route without allowing for vacancy risk, management...