Around $205 shipped (although that is after I backed out a few higher priced pieces that I knew I had sitting around - BURP's, and a few Technic connectors, etc).
The designer tried to use mostly pieces that were in the set (if purchasing a second set). I believe that 1000+ are avail in the Lowenstein set (and you would need to purchase the other 600 or so).
So you could have spent the $200 for a second set, buy the extra pieces for around $65 or so (plus shipping), and still have 1,000 nice new castle pieces left over.
The big decision factor would come down to what the value of a new/sealed Lowenstein set is/will be.