Kerbal Space Program

The mass of the Rockomax HubMax Multi-Point Connector is vastly disproportionate to other parts. So much so that using a full FL-T200 fuel tank and four BZ-52 Radial Attachment Points is actually .215t lighter. While the direct cost is slightly less expensive than alternatives (900 vs. 1183 for version with empty FL-T200), the added mass means it is almost certainly more expensive in all cases. With Making History, six SP-S12 Structural Panels can be used and are both lighter and cost much less (cost 180 mass .45t).

Alternatives (all with four BZ-52 Radial Attachment Points unless otherwise mentioned):

Empty FL-T200 fuel tank: cost 1183 mass .285t
Full FL-T200 fuel tank: cost 1275 mass 1.285t
Empty FL-T400 fuel tank: cost 1316 mass .41t
Full FL-T400 fuel tank: cost 1500 mass 2.41t
Structural Fuselage: cost 1380 mass .26t
Medium T-12 Structural Tube (MH): cost 1360 mass .26t
Medium-Short T-12 Structural Tube (MH): cost 1260 mass .227t
6 SP-S12 Structural Panels no BZ-52s (MH): cost 180 mass .45t

I would say that the heaviest it should be is .4t and .25t would make the most sense IMO. Either that or it should be moved to be a starting tech with the expectation that lighter parts will be used once available (however even then it seems like it should be lighter so that an array of fleas could be used).