Waves is good but expensive both to buy and to keep updated and tbh you often find that in their large packs like Mercury/Platinum etc that you don't actually need or use quite a few of the plug ins.
Personally for mastering itb I think there are are good plugins from the likes of Flux, Sonnox (Sony Oxford) and Proaudio at the more expensive end and Voxengo, Stillwell, PSP at the less expensive end. Flux etc are as good as or better imo then the equivalents from Waves - and you only have to buy the ones you actually need/want.
Also for getting started the all in one Isotope v4 is good.
If you want to get in to mastering in a big way I'd invest in - if you haven't already done so - the best room acoustic treatment and monitoring that you can get. Basically if you can't hear the mix accurately then you will make mistakes mastering. Once that is done then I'd look at the AD/DA conversion and in line with that good mastering software that lets you do red book cd authoring. Then invest in expensive hardware and software effects/processing like waves' Mercury.
BTW and fwiw we are in the process of converting a room in to a mastering studio so I'm kind of going through the same decisions as you are. A lot of our stuff here is fine for tracking/recording but not mastering grade and I have to convince the wife that we need to invest more cash
(and hope she doesn't add up how much is being spent
). She made a large choking noise the other day when we were talking about our AD Conversion.
I figured there might be many things in Mercury that I would not need. Thanks for the info on the other brands to check out.
Converting a new room to a studio sounds pretty exciting. Would love to see some before and after pics.
I know what you mean about the cost of some of this stuff. I just tell my wife that since we spend so much money on my daughters sports camps and clinics that we can do this for our son since he is not very active into sports and is into music. So I have doubled my office above my garage as my studio right now. It has wood laminate flooring so I put down a big area rug and we set drums up on that and I face the Kick drum right into the small loveseat to baffle the bass. The walls only go up about 4 feet before the ceiling starts to slope in on you. It follows the roof line. I think this really helps the acoustics because its not so square. I am using M-Audio BX5a Monitors and they seem to be pretty nice so far. I also have a set of Sennheiser headphones. That along with the Macbook pro and Apogee Ensemble and some mics and JDI Boxes, Cables adapters etc, etc, and I am already into this thing by about 5 to 7 grand. Bad thing is when I get a new Sweetwater catalog I sit there and drool over all the things I still want....... Anyway thanks for the feedback. I will probably be posting some more in the following days. Starting tonight I have to get serious and start spending a couple of hours a day finishing up vocals and then working on the mix.