Buying one for $400 AUD delivered is below MAP + being sold on eBay it won't be covered under warranty. So you may save yourself a couple of hundred, but just pray it never requires servicing.
Agree with above though, unless you're planning on driving interstate with it, the V1 shits all over the Bel STI
And just in case anyone wants to chime in and refer to the "V1 versus Bel STi" report from Craig Peterson from radartest.com, or the "V1 versus Pro78 article" (also by Craig Peterson) that is referenced by radars.com.au - just keep in mind that Craig Peterson is a PAID CONSULTANT by Beltronics, and after a huge fight with Mike Valentine over a decade ago, he never praised the Valentine One (V1) in his articles and tests.
He also tried to sabotage the Guy's of Lidar test one year:
http://www.guysoflidar.com/march-2007/sabotage.html
Unfortunately the average consumer doesn't know all (this type of) "insider info" in the radar detector market. It was one of the primary reasons I built the delonixradar site many years ago - to educate consumers and [try] to put and end to the BS - particularly in AU (there's still soooo much BS unfortunately)