Help me out a little here with Waves Plug-ins...

Your client is wrong...
 
Not to make you feel bad, but it isn't the plugins. It is learning how to use them that makes the difference. Waves plugins, though great, are not magical. I have them and, for the most part, can reproduce my results using Sonar's tools. The "for the most part" aspect are the things that certain Waves plugins bring that are not in Sonar's tools, like emulations of certain hardware.
 
Mixing is a skill like any other and takes time and practice to learn. Be patient with yourself. You should avail yourself of the Techniques and Songs forum to get advice and help for your own mixes.
 
Regards,
Dan

Jimbo,
 
I've got about 25 or so Waves plugins as well as plugins from Eventide, Melda Productions and others.  Waves have always been stable for me.  Honestly, I've only been able to buy them when they were on sale, so with the Thanksgiving, Black Friday, Cyber Monday, etc. sales, I have been slowly building them up over time.  Sometimes they are on sale for as low as $29 as well as offering a some of freebies for promotional purposes.  I just picked up Trueverb this weekend as a free plug.
 
Now, as far as them being better than other plugins, including those offered by Cakewalk contained within the DAW, it is my opinion that they are not significantly better than what comes with Sonar.  Waves plugins certainly are equal to or might exceed Sonar's somewhat since they are a dedicated company that specializes in audio plugins and that's what they do.  They do provide more variety of plugs overall if you're looking for certain plugins that Sonar doesn't offer, even though Sonar offers a lot.  So, in brief, I do not believe that having Waves plugins are going to make or break your mixes.  Plugins from other companies, such as Izotope, ToonTrack, etc. will also serve you and get the job done.  
 
It sounds like the client wants you to process your audio at certain steps or levels in your mixes, either to fatten up, brighten, compress, etc. tracks or final mixes, including "mastering" before you send it out. You indicated that you have not been mixing very much until lately.  Perhaps some folks here on the forum can help you with that.  Either way, you got the most important part down: the Music!  You just need some help with mixing I'm guessing.
 
Regards

watch a few videos on mixing / mastering. (You can google them, there are a zillion of them out there) Some are better than others, but most should help familiarize you with the landscape. You will see some common techniques, that should get you started. Waves is just a brand, there are a lot of good plugs out there, and dare I say, the toolkit you get with Sonar should be enough to get you good results when properly applied. Come back and post when you hit snags, and the community will help steer you down the right path. 

Someone claims to be able to "hear" you're not using Waves? Wow, they must have the hearing of a cat. Or did they ask you "did you use Waves?" and when you said "no" then announce that you "have to use Waves"?
 
Seriously... Which Waves plugins can they clearly hear you're not using? I've a bunch of Waves plugins, and the ones I use in Sonar are mostly the effects that either Sonar Plat doesn't have, such as hardware emulation of exciters, specific antique and quirky consoles/eqs or Reel ADT's flanging, and things like the Waves multi-band compressor that can be side-chained per band. Plus a very few I prefer over Cake's offerings, like the Waves NLS. I also use BozDigital, D16, PSP, Melda, Overloud....
 
I use Waves stuff far more in Logic Pro, but that's because many of the plugins that come with Logic aren't as good as the ones that come with Sonar, in my personal opinion at least, so there are gaps in Logic's plugins which Waves (and other plugin makers) fill.
 
I would defy anyone to listen to an entire mix and spot that the guitar track has, say Sonar's Quad Curve eq running on it rather than Waves' equivalent plug. Or the mix bus final limiter was Concrete Limiter rather than Waves L2. And for fx plugs there are many companies making stuff that's as good as or better then the Waves equivalent.
 
Unless you have to supply the entire project in Sonar format so they can see what you used just don't worry about it. By all means get Waves plugs that you think might be useful to do a specific function, but don't get them just because they're "Waves". Work on improving your mixing and if questioned about plugins nod, smile sweetly, enthuse about how AWESOME Waves are and thank them for their advice. Then take their cheque.

Now way he can "hear" Waves plugins in a mix.  I have a friend that works for Waves and he couldn't even do that.  


At least you didn't pay the "retail" prices, those are absurd. 
 
I own a number of their plugins, most never get used since the ones with Sonar X are solid.  I've also run into a number of free or dirt cheap plugins that I even prefer to Waves.