I took a look at it earlier this week and determined it wasn't cost effective for my race. Even a tiny world with (5 Monoliths IIIs) * (the pop bonus of 5% + 20% race bonus + 20% happiness) * 1.3 (robotoid facility) * 1.3 (system robotoid) comes out to be more than the remote mining value.
Mainly it's because the remote mining doesn't get a single one of the bonuses at all, from what my testing showed me. Not even at the system level.
You don't even need to time the build for turn 149, just keep it in place and abandon the planet on turn 150. It's also the only way I can think of where your score could go up during a turn, as opposed to between turns.
Good thinking btw, that's the sort of thing you need to be trying out when in a contest like this.
-Drake
[This message has been edited by Drake (edited 09 February 2001).]