[Edi]

The Dreamlands freespawns have a gold cost of 1, some of them may have gold cost of 2. That means that in general every 15 freespawn costs 1 upkeep. It cannot get cheaper than that and still have upkeep.

Supply multipliers can be adjusted on a per game basis from the game options unless I remember wrong, and in any case it can be adjusted via mod so that you do not run out of supplies.

I do not see a need to alter LE R'lyeh in the manner suggested, because the request seems to stem from a particular type of game and the parameters probably do not apply universally.