You said it was a BIIIIIIIG question
How can anyone even give you an estimate without seeing the bass? What does "new neck roughed in" mean? How rough? Is the FB attached? Fit and shoot fingerboard coupla hundred at least. Maybe a coupla coupla hundred. It has a soundpost - GREAT NEWS, but is it in position? is it in the right position? Does it have a bass bar? Still attached? What about a bridge ... you might need a bridge, yeah? A new bridge fitted is a coupla hundred at least. Secondhand strings? What condition? Will they work on that scale length? New strings coupla hundred.
Could be a "put it all together and play" situation or it could be a "complete makeover necessary"!
Fair crack-o-the-whip mate, you need to find out more about the bass.