Not finding an organ plugin in platinum. What's a good one out there for a reasonable price?

VB3. I have tried others.  VB3 beats all that I have tried including the B4 which I liked very much.

Dim pro has a good bunch, There's a Hammond B3 patch I bought on sale for $8.  I even use the TTS-1 organs. Then go to KVR and try a bunch there. Lots of good organs free. 
And it depend on what you mean by organ as there's the 60's portables and then of course the big heavy Hammond complete with Leslie sim. I must have 100's on hand and all but the B3 patch came free. 

You are correct there is no dedicated organ plug-in. Have you looked at any of the bundled synths for organ presets? Here are some of the bundled synths with organ preset covering a variety of organ types:
Cakewalk Sound Center
Dimension Pro has several folders for organs including a virtual B3 under Expansion Pack 1 > Organs. Here is an image detailing how the functions are mapped on the DPro UI for the virtual B3

GrooveSynth
PSYNII
Rapture
Rapture Session
TTS-1
Z3ta+
 
If you cannot find what you are looking for in those synths or just want a dedicated organ plug-in, check out VB3

http://www.airmusictech.com/product/db-33#.WG5tIOs76rU

Just picked up this DB-33 and have been exploring. Really nice presets. Versatile. B3 GUI with controllable Leslie speaker cab for that classic rock sound, jazz organ, Gospel, etc. Cool GUI. Unlike some I've seen, this actually has a super controllable Leslie rotary speaker cab where you can tweak both the rotating horn and the bottom-end drum speakers. Sounding great so far.

Worth a look for sure.

Billy86
http://www.airmusictech.c...uct/db-33#.WG5tIOs76rU

Just picked up this DB-33 and have been exploring. Really nice presets. Versatile. B3 GUI with controllable Leslie speaker cab for that classic rock sound, jazz organ, Gospel, etc. Cool GUI. Unlike some I've seen, this actually has a super controllable Leslie rotary speaker cab where you can tweak both the rotating horn and the bottom-end drum speakers. Sounding great so far.

Worth a look for sure.

+1 for this. I have it to and like it very much.  The person to ask on this forum is Bitflipper. He knows organs well. 

I like VB3 a lot, too. It's very capable!

thats what she said

Native instruments Vintage Organs are great. Especially when you tweak the drive knob up under the hood. Air knob is nice too. I have a drawbar controller for the software as well. Gotta work the drawbars!! I own a Hammond B3, CV, and a A-100. ;) Nothing beats the real thing! When I don't have mine handy I use NI.

I think Rapture Pro (it might be DimPro) has the "Jimmy" preset.  That is what I use most of the time.