Yeah, but My dad had a Texas Instruments calculator that cost like $250 in 1980. It weighed as much as a pint of ice cream, and It could add, subtract, multiply, and...divide. A big part of the cost of the original memorymoog would have been the digital components, which are trivial now.
Also, I took a look at the circuit boards in the Little Phatty. They look like breadboards. Hell, the original Moogs basically were breadboards. I've worked on electronics designed to fit into very tight form factors, and I'm pretty sure you could fit 3 Little Phatties on one voice board. The boards aren't optimized for space, because they don't have to be. The keyboard and control panel are the limiting dimensions, and they're huge. I opened up my Rogue, just to see what's in it. (It has most of what a Phatty has: 2 VCO's, filter, envelope, LFO.) Anyway. It's pretty much a breadboard. Minus the controls, there's almost nothing there. You could but it all on a board the size of 2 credit cards easy.
The LP boards are probably optimized for heat dissipation, and the boards are made to fill the space so they don't have to float in there. Cost is another issue, and I can't speak to that as much, but look at something like a Virus. Hugely complicated. Basically a computer optimized for sound production, in a very high end case with CNC milled wood end caps. Made in Germany,(not China) for about 3 grand. I know you can't compare digital and analog gear, but I think it's a not unreasonable benchmark. I do appreciate what goes into making these instruments. I just see a lot of ...potential.