Vortex Sound Research

Im looking at buying a Music From Outer Space DIY synth, and i notice that they seem to be far cheaper than a eurorack of the same size. How does the MFOS compare to a standalone hardware synth, (what normal synth would you best compare it to? Behringer D? Minilogue? Or something nicer?) How is the quality compared to something like the previously mentioned synths? Also, are there any other cheap diy synths/synth kits that give a lot of options? Finally, if i get a MFOS, how expandable it it past the regular expansion module.