Sean Hart, if you are harboring the mindset that you have to buy all
doepfer modules because you have a "limited" budget of $2000, you
should get rid of that mindset. Not all doepfer modules give you the
most features for the least money. Some modules from other
manufacturers cost less and even have more features that the doepfer
equivalent. You would be doing a disservice to yourself if you didn't
check out modules from every eurorack manufacturer.

One more thing! Don't be turned off by a $300 module. Some modules
that have a high price tag can do everything that three lesser modules
can do. Such as these:

http://www.bigcitymusic.com/product.asp cat=new&pid=1000593 (great
alternative to doepfer's envelope follower)
http://www.ear-group.net/model_13.html (buchla-style module)
http://www.ear-group.net/model_25.html (multi-functional audio processor)
http://www.ear-group.net/model_26.html (multi-functional signal processor)

Doepfer: http://www.doepfer.de/a100.htm
Sold by Analogue Haven: http://www.analoguehaven.com/doepfer/

Cwejman: http://www.cwejman.net/cwejman.net/modular.htm
Sold by Analogue Haven: http://www.analoguehaven.com/cwejman/modules/

Analogue Systems: http://www.analoguesolutions.com/
Sold by Big City Music: http://www.bigcitymusic.com/dept.asp cat=new&idp=15

Plan B: http://www.ear-group.net/planb_start.html
Sold by Noisebug: http://www.noisebug.net/

Analogue Solutions: http://www.analoguesolutions.com/
Sold by Noisebug: http://www.noisebug.net/

Actually, there's a large handful of eurorack manufacturers on Analogue Haven;
MFB: http://www.analoguehaven.com/mfb/modules/
Metasonix: http://www.analoguehaven.com/metasonix/
Harvestman: http://www.analoguehaven.com/theharvestman/
Elby Designs: http://www.analoguehaven.com/elbydesigns/
Livewire: http://www.analoguehaven.com/livewire/
Tip Top Audio: http://www.analoguehaven.com/tiptopaudio/
Makenoise: http://www.analoguehaven.com/makenoise/

You might want to check out this as an alternative to the doepfer ring
mod. I've heard good things about it:
http://www.analoguehaven.com/makenoise/moddemod/

There's a lot to choose from. Choosing modules is a lot like playing
minesweeper. You never know when you're going to get a module with an
unexpected feature that really makes you unhappy with it. Make sure
you get at least one opinion on ever module. My budget was $1000 when
I started building my synth. Because I was unhappy with so many
modules, I ended up spending more than $3000 (also partly because I
HAD to get some things or I'd feel my synth was horribly incomplete).
Check out my ongiong modular thread just to get an idea of what can go
wrong: http://modularsynth.net/viewtopic.php t=1792&start=0