IMO
Priority 1 fully expand land - because land parts are next to impossible to get at higher levels. People used to park at level 10 for two months and do this. Never ever sell a land part until you are done.
Priority 2 expand storage to at least 300 since it supports everything else
ignore the CoM until much later when you have epics making gold coins daily.
The game is progressive. They added the CoM after the Epics, which were added after the things before them. I played it like this: land expansion > built support structures > build residences > gold key production > specialty buildings > expanded storage to 350 > upgraded buildings to Epics > upgraded storage to 500 > upgraded rest to epics > played C0M using all my gold speed-up coins from the Epics> got exhausted > rearranging city and waiting for further land expansion in future release
