That price seems kinda high for a 10 year old waverunner. A new 2016 VX lists for $10,500 CDN (plus a trailer which usually runs about $500-700). You should be able to get a discount off MSRP as well (maybe $700-900).
So the 10 year old 2006 one is $6500 and a new 2016 is about $10,300. i'd offer more in the $4500 range.
Having said that, the VX waverunners are bulletproof---they're universally used by rental companies the world over and typically run 800-1000 hpurs with little but routine maintainance. (I have 2 waverunner FXHOs---the next step up)
See if the owner has any sort of maintainance records and whether the ski was winterized before it was stored last (especially fogging the motor). Im sure its too cold for a rest ride but have him start it and listen to it run---you can safely run them 20-30 seconds without being in the water.
This is a great site but there's another specifically for PWCs---its
www.greenhulk.com Lots of great folks on that site like this one willing to help a newbie oit!
There's a guy on there who posted a couple days ago about his two new (used) VXs--- one a 2009 with 25 hours and a trailer for $4800 and the other a 2013 VXR with 25 hours and a trailer for $7000. Both were in US dollars.
http://www.greenhulk.net/forums/showthread.php?t=242869