Wavelab is a great piece of software, but I'd look closely at the different versions and see what you really need.
I own v6, 7 and 8 myself, but still v6 is what I'm using 95% of the time.
Not being a WL power user, v6 gets the job done nicely for me and imho has the better UI concept by far.
My main WL use is batch processing, go figure.
Likewise, basic mastering can be done in any host just fine, maybe adding one or two dedicated mastering plugins would be an alternative ?
ymmv, certainly,
Rhino