My STi came with the factory boost gauge option and I yanked it out since I already have GReddy gauges, including boost which I carried over from the WRX.

The boost gauge was used for 8 days and is in perfect condition. Includes directions and all necessary parts.

subaruparts.com has this for a discounted price of $189.

I'm selling mine for $150 shipped.

http://www.subaruparts.com/catalog/subaru/H5010FE041.jpg

Sold!