Hi and Welcome on Edaboard,
You are just on right place for this, all You have to do is to use search white field in upper right corner and search some design chooises and read debate about this there is lots of materials, also circuits, parts,....
Looking from corner of electronic amateur and small production cost of uC for this usage it does not matter, because You will have more costs on other side and components. You should look what You get from uC and how it is implemented into design. Cost of lots uC today is not high compared to case of device, trafo, copper wire, lcd, shunt, sensors,...
If intend to have manufacturing big serie of devices, then all parts should be checked with price, and both eyes should look to China.