Personally im not against the current cost of the T4 Shipyard. Its very possible to build, if people allow their standards to go down a bit about how perfect a manufacturing planet has to be. It doesnt have to sit on a homeworld for example, that already has to stack deep mines for all resources.
However if the main irritation of people is that they really HAVE to use their homeworld as a manufacturing world, then at game start, make sure people start with a large homeworld, then people can choose if they want to stack deep mines OR fill the planet with Shipyard etc. Currently the spawning algorithm means players can get a homeworld of any size. Some started with size 5k homeworlds (i started with a size 8k) while others can start with a size 23k homeworld. Its far too large a variation as a 5K or 8K homeworld is so small that it can hardly support deep mines + power/ EC even if you demolish all labs and shipyard.
For me i have terraformed another larger world for the T4 shipyard then use Cargo transporters to move the resources it needs there from in system.