Hi denisdenis,
Valley Lakes is the old Niddrie quarry site, lots of cars dumped in the hole in years gone by. Im sure its all cleaned up now.
There was a bit of a outcry when it was first released over it being advertised as Valley Lakes,Niddrie because only 10 or so blocks were actually zoned as Niddrie (percieved as a little more cosmipolitan) and the remainder zoned East Keilor.
As far as prices and/or value for money I am unsure as I have not really looked into the estate. Generally in Niddrie you can buy a weatherboard house on 600m2+ for 350k to 450k depending on proximity to Keilor Rd. 350k in East Keilor will pretty much buy you anything you like.
Hope this helps,
Bernard