There is a company out there that has these discs for a little cheaper than what sony offers them. The cost would be $44.99. This is the company that we purchase our discs from when we need them for various computer. I went to their website www.recovery-disks.com and typed in your particular model number and came up with the following website:http://www.recovery-disks.com/sony-vaio-vgn-ns190j.html
There they're listed. We've used this company before to purchase restore disks and recovery disks to restore customers computers back to factory after installing new hard drives or at their request.
Good luck on your search for a disc!