He's moved on to proving he's a moron to a larger audience than MSNBC SBB. Your criticisms are dead on. The ISS has a volume comparable to skylab with a far higher cost due in large part to modular design. Modular spacecraft using cryogenic propellants would require a launch rate never before matched by medium class boosters. Multiple launches mean a greater risk of at least one failing which with cryogenic propellants would mean starting over from scratch.

Anyone who starts off with strawman arguements based on "common sense" which are totally wrong based on the rocket equation should just keep his mouth shut. The size of the rocket doesn't mean much in terms of economy of scale in pound of rocket/pound payload/pound fuel. Economy of scale comes in launch prep, avoiding modular construction, and in sheer mission capability.

Regards,
Mark