Order your design through PCB123, and Sunstone will send you the Gerbers free-of-charge. Just email support@sunstone.com and we'll send the Gerber file set via email.
If you prefer to order your Gerber files without building the boards at Sunstone, we now only charge a $100 file-generation fee. Contact support@sunstone.com to learn how. Gerber File Changes for PCB123.