when i testdrove the 06 WRX and also studied the web specs, i didnt notice any stock turbo boost gauge.... but when i read some former posts here, theres mention of a stock boost gauge.

so do they come with a stock boost gauge? where is it?

It's optional and on the steering colom

Yep still an option. Subaru sells it either by itself for mounting on the steering column or as part of the 3-gauge pod that replaces the clock.
The factory gauges are overpriced for what they are, you can do better aftermarket.

When I bought my 2004 WRX, I wanted a boost gauge too. But seeing how overpriced, small, and didn't blend well with the interior the factory one was...I decided to wait and get an aftermarket one. Ended up getting a VDO setup with a dashtop mounted pod for about $100. Much better in my opinion...I'd say look around and find one that suits your tastes for a lot less cash.

http://www.i-club.com/reviews/data/107/24719robs_wrx_interior_lights-large.jpg

must be an option in usa. theres no mention of a boost gauge in canada's subaru website...