Williamstown Heritage rennovation - build costs?

Hi all,

i know this might be a bit of a "how long's a piece of string" type question, but i'm trying to crunch the numbers and figure out if a purchase/reno/sell is worth it or not.

Property is in one of the good streets in Williamstown South, single front, victorian, heritage, usual deal.

i think land size is approx 270sqm and only a 2/1/1 at the moment.

What i'm trying to figure out is how much is an approximate building cost to do a full rennovation, plus a "first floor" for the back half of the house?

I found this link:http://renoaddict.com/2015/03/04/real-reno-single-fronted-heritage-homes-two-story-transformation/
Albert Park, single front, but seems like it needed a FULL build, the Williamstown prop we're looking at seems to be holding together ok.

The Albert Park build had a $420k budget, which seems a lot more than what would be needed for the Williamstown one?

Does any have any experience in doing reno's in the Hobsons Bay council area?

I was working on a $200-$250k build cost? too low? For this part of Williamstown, the finish would need to be high quality i would think.

The other problem is i have no idea of expected sale price? The Albert Park one killed it, sold for $1.82, which made the whole exercise very worth while but i have no idea what a really nice say 3/2 victorian would go for in Williamstown South? I tried searching sold listings, but couldn't really find anything comparable unfortunately.

If anyone can provide any help/insight/guidance, it would be monumentally appreciated!

Small world as I've been closely following this property myself. Don't believe the price range, this mob have a reputation for under quoting.