Hmmm...sometimes I even amaze me...OK, got the additional module expenditure down to $986, a $238 drop. And strangely, in the process I upped a bit of the functionality, although the initial build was a bit better fit, I thought. New version's in the same position in this thread, so have a look...but here's what was changed:
This version changes the extra VCO (Plaits) to a pair of more conventional VCOs, a Ladik and a Noise Reap uBermuda, which is a somewhat weird thing that can go into internal feedback behavior, sort of like sending a VCF into self-resonance. Went to a single VCA/mixer with those also.
Quad LFO was changed to a TAKAAB 3LFO, which offers two waveforms in a staggered timing setup. ADSRs are now Ladiks, both with normal and inverted outputs, plus I was able to squeeze in a dual AD Ladik to give you two more envelopes. I switched out the Ladik dual linear VCA for a Noise Reap pair. Eowave Poles now handles attenuation/CV/inversion, and the Tiptop Fold also offers a suboctave generator, which wasn't there before. Same sort of 4-pole transistor-ladder lowpass VCF, albeit Doepfer's version which loses the dual input mixing...but the Fold has that now, so nothing lost there.
So...yeah. Filled cab, again. Functionality a bit different and, like I said, upped a bit in a few ways. And closer to the $700-ish budget line you quoted.
As to what to get first...hmm, that's a puzzler. I sort of build things as a 'unitized' set of subsystems, which is how I'm used to modular gear working (and, for that matter, a lot of prebuilt stuff). My suggestion would be to just add along as you can, and if you can kick things down a little more with used purchases (there's loads of used modules out there if you look), then cool. Otherwise, the only other way to reliably knock things down further is to go with a bunch of DIY kit modules...which is an option if you're OK with some soldering and assembly, but otherwise, this is not too shabby.