They're semi cheap. just not the cheapest but PSP has a mastering package and a mix package which bring forth some serious damage or quality, whatever you fancy. I dunno if they have any demo's online but I would certainly give them a go. So far I've worked with the Vintage warmer which will go for allround channelstrip single or multi band compressor. The kit also includes the MasterQ, quality parametric equalizer, perfect for mastering!. Haven't tried it yet but looking at the quality of the vintage warmer eq, things can only get better, I definitly put my money on it.
The mixpack has four plugs which arent the usual utilities but so friggin' nice, I've tried most of em, especialy the mixtreble and the mixpressor. The mixpressor is capable of making the set violently alive for what dynamics concern, i've put this bay to work on some techno and breaks and it's outcome is simply stunning. I've used the mixtreble to balance out the trebles frequencies, the plugs enables altering hiss, transcients, frequency widening and spatial enhancing. This can make a dull mono sounding source into a hifi stereo signal.
The other two are a mixsaturator and a mix bass which I haven't really tried but are definitly a good addition to the mixpack.
Every plug supports resolutions up to 196kHz and plug format includes RTAS.
Go check the demos ( RTAS also ) they should convince you by simply playing with the presets, the kits are relativly cheap if would compare it to other " high end "mastering/mixing packages when it comes to quality/efficieny or simply practical use. To my opinion best best in the cheapest price range anyway.
http://www.pspaudioware.com/plugins/mix.html
For reverb or delay I would say check out the same thing, there's also a free pianoreverb for download also in RTAS I believe which is very good already. They also made a pretty good emulation on the lexicon pcm42 which is a common studiopimp artefact, called the PSP 42 ( PSP 84 for a blown up version, definitly sickening ) I had been using it for quite some time with great pleasure untill I got aquinted with the logic tape delay and IK multimedia Amplitube which has a stomp box with good warm sounding (spring or not) reverb, delay, wah, chorus and overdrive. It gives it much more a harmonic blend than most clinicly correct reverbs which just sound to sterile to blend with the rest ( but you can use the mixtreble to balance this out ).
Other Reverbs I've really liked are the 480L ( another emulation from Lexicon ) which is simply breathtaking, they definitly got the algorhtymns right on this baby. Another one but certainly not the least ( I've been using this one the longest in my vst experience ) is the Studioverb plugin which comes with the DSPFX package. I dont know the whole story behind the package but it's suppossed to be sold with a certain soundcard and contains everything you need except a compressor. The downside about it for what concerns you is that it's only DX ( 1.0 ) or standalone, which isnt a problem in my case since fx go through auxilaries to avoid latency issues and my daw's handle DX. I dunno about this on pro tools. But to give you an idea of what you get and with great quality;
StudioVerb, AcousticVerb, Optimizer, Aural Activator, Parametric EQ, Flanger, Chorus, Multi-Tap Delay, Pitch Shifter, Auto-Panner, Tremolo, and Widener.
and that for $149, you can pm me on some more info. They're also asking $99 for the 6.2 update but there no info on what the update really is about. So that sucks.