I never once advocated building solely monoliths right off the bat... I only start building them after my economy is well off and can support the deficits incured with Monolith construction without problems (and I start off slowly; I don't just suddenly have 50 worlds start on Monoliths all at once). Also, absorbing a few minor empires early on helps cover those deficits too.
It is a good idea to build a SY as the first facility on new worlds in general because if you need to use them, you now have a bunch of SYs available to build colony ships, warships, and whatever else you want.
The cost to build monoliths is immaterial (esp. when you wait until you get a strong economy going before building them). What else are you going to do with those resources, build more ships than you need?
Also, keep in mind that once my Monolith economy is going, I build them on all resource worlds. A 100/30/30 planet produces more with Monoliths than just Mineral Miners, after all. Will it take longer to even out? Sure, a few more turns. Big deal.
Furthermore, Monoliths are not for small empires. They are for large empires (100s of planets). Starting to build Monoliths when you only have a few dozen planets (and esp. when there is still a lot left to colonize) will only get you killed.
Building a Robotoid Factory III after the 4th Monolith often takes just one more turn than a Monolith, and gives many more resources than a Robotoid on a planet with normal miners does (as there is much more base production).
The fact that monoliths take longer to build can work to your advantage. Normal economies max out a lot sooner than a Monolith economy (and a proper Monolith economy will not be too far behind the normal one when this happens), while the Monolith economy still has a lot of growth left. I would have to disagree with the statement that some resources now are better than more resources later. In most situations, waiting a dozen turns or so is well worth the investment. If you are being destroyed, then of course building Monoliths is not going to help much. Emergency situations call for normal miners.
Keep in mind that it is rather easy to get Monoliths built in 3 turns a piece on all worlds with more than a few facility slots (HI, 120 const, SY III, Jubilant pop). Again, the resources to build them are only an issue if you are engaged in a losing war. If you are in no wars or in a winning war, then the high cost to build Monoliths is a null issue.
And by the way, I know how to do algebra.
Here are some numbers for a PBW game I am in:
Huge (255 system) map, 17 players, turn 142
1st: 8.7 M points, 299 planets, 4.2 M resources
2nd: 4.5 M points, 142 planets, 1.1 M resources
3rd: 4.1 M points, 117 planets, 387.5 K resources
4th: 3.7 M points, 158 planets, 507.5 K resources
Guess what the 1st place player did? You guessed it, Monoliths. 2nd place has been building Monoliths recently, but is very far behind. 1st place can not get enough ships built to use up resources, so many 100k of them get wasted each turn (he lost something like 140 ships in an ongoing war thanks to those damned Talismans). And, 1st place doesn't even have HI in this game (he was a PBW newbie when it began, afterall).
There was another empire that was in 2nd for the whole game, and using normal miners. He managed to destroy several empires too. He surpassed 1st place player for about 20 turns, but his unrelenting aggression forced the peace loving races of the galaxy to go to war to stop him. He is in 8th now. When (current) 1st place entered the war, each of them was producing about 1.0 M resources, and he had more planets than (current) 1st place did. This was some 50 turns ago.
So in summation:
Short term: Monoliths = bad
Medium term: Monoliths = roughly equivalent (with only low net loss)
Long term: Monoliths = super good
If you only care about short term gains (such as early game, small maps, early wars), go with normal miners. If you care about long term gains (large maps, mid-game, no early wars that are not resulting in you steamrolling over a minor empire), go with Monoliths.
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About Remote Miners:
Again, using them is only good in the short term. In the long term, it is much better to build planets out of asteroids and build normal miners or Monoliths on them (as the situation dictates).