I would suggest going with the Universal Audio Precision Mastering Bundle which is $500...
The bundle consists of these 3:
The Precision Multiband
Precision EQ
... and Precision Limiter
The only thing it requires is a UAD DSP card... which is cool cuz that's where all the audio processing takes place, similar to Pro Tool's TDM plugins on their Accel cards - this takes the strain off the computer, which can be much-needed since these plug-ins upsample to 192kHz...
Now the original version of the Universal Audio DSP card (UAD-1) can be had used on ebay for dirt cheap ($50-100)... 1 card would give you enough power to master a couple songs in the same project...
If you wanna go for the gold - UA recently released the UAD-2... and their most poweful version, the UAD-2 Quad is 10 times as poweful as the original...
If you cop one of those, you get a $500 voucher which will allow you to get the Precision Mastering Bundle for free... and it also comes ready 2 go with 7 'mix-essential' plugins...
Here's a link to the cheapest deal I found for the Universal Audio UAD-2 Quad Flexi - (which is the one that includes the $500 voucher)...
http://www.wwbw.com/Universal-Audio-UAD-2-Quad-Flexi-500466-i1415357.wwbw?source=TWFRWXX&mr:trackingCode=41BDC271-0319-DE11-9BD3-0019B9C2BEFD&mr:referralID=NA
Plus they gotta deal at their online store which will give you 30% off if you get 3 or more plugins (before July 31st) - so u can pimp ur voucher even further....
http://www.uaudio.com/products/store/index.html
But yeah like I said you could get the UAD-1 offa ebay, hit up Universal Audio's customer support & get a demo-reset - wich'll let you try all their plug-ins for 14 days...
If you prefer to go the economical route, you could always get a UAD-2 later and use it with the UAD-1 simultaneously... I have both a UAD-1 & UAD-2 working together in my setup & all is well!!
I would mos def reccomend UA over Waves...
If you ever think about buying from Waves, google 'WUP' first!!