For a limited time, developers can sign up for a 50 percent savings on the Project Tango Development Kit, dropping it to just $256. The codes are limited in quantities, and only available in certain areas, so if you are interested in picking one of these up, you'll need to act quickly. To get the savings, you'll need to meet the following criteria:
Codes are limited to the first 400 people who sign-up, and to select countries where devices are being sold in the Google Store (Canada, Denmark, Finland, France, Germany, Ireland, Norway, South Korea, Sweden, Switzerland, UK and USA). After submitting your information you'll be emailed your individual code. Codes are good for 5 days upon receipt. Please allow up to 72 hours to receive your code via email.
The Project Tango Development Kit is meant for developers who want a reference tablet to try new things on. It features a 7-inch display, 4GB of RAM and 128GB of storage. Inside is an NVIDIA Tegra K1 processor with integrated depth sensing and motion tracking cameras. If you are interested in picking up one of these kits, you'll need to act quickly.
Source: Android Dev (Twitter)