HAving reveiced amazon vouchers for Christmas.... I've had a looking and spotted Ozone 5 on Amazon.
 
does iZotope allow 3rd parties to sell their software?

Probably. I doubt amazon is doing it illegally

yes amazon 3rd party vendors sell Ozone / isotope products.
 
it is boxed version, no digital download of license though.  
 
you will have to add shipping costs to your total price.
 
completely legit, legal and proper :)

Yup - it's all good.
I bought my copy of Ozone 5 from Amazon.
 

Yup, bought my copy of Alloy 2 at KVR.
 
Check out a list of vendors allowing license transfer at KVR (thread no.9) :
 
http://www.kvraudio.com/forum/viewforum.php?f=43

Thanks.... that put my mind at ease...   next question though... anybody heard of an a future upgrade to ozone 6 or do you think it will be a while before it gets a revamp?

You can nearly always get better prices from stores with izotope stuff. Secondhand on kvr is excellent too.

You would think they would bring out 6 but the last improvements were generally to speed up the process and didn't alter the end result much, if at all.

5 was released November 2011. Unless they are changing the end result it may be more cosmetic again or lots of presets.