Sketchup Pro, Single User License, USD $490, Save USD $100

Started up Sketchup Make (the new name of the free version of Sketchup) today, and on the splash screen was a coupon code for $100 off Sketchup Pro from the Sketchup online store.

https://store.sketchup.com/product-view.ep?pID=COSU2013NEW

If you don't need the added features of Sketchup Pro, Sketchup Make is completely free, and includes a trial of Sketchup Pro.

Features in Sketchup Pro: http://www.sketchup.com/content/why-go-pro

If you are a student, education licenses can be had from a local reseller for AUD$60+GST (http://www.4site-architecture.com/sketchup/buy.html). I do not know how student status is verified however.

The license includes one year of upgrades and support. After that year, another year of upgrades and support can be had for USD $95.

Update
I misread the coupon description, it's $100 off, not $100 for the license unfortunately.