I saw this mod and in the back of my mind, I was like AWESOME!! But now after 8 hours I have yet to build a single Rainbow beacon, and here is why:

The first tier requires 5 beacons to achieve, after that, it is a factor of 10 from the previous tier. You can see how this adds up exponentially.

Beacon Plain = 1 beacon cost
Red Beacon = 5 beacon cost
Orange Beacon = 50 beacon cost
Yellow Beacon = 500 beacon cost
Green Beacon = 5,000 beacon cost
Blue Beacon = 50,000 beacon cost
Purple Beacon = 500,000 beacon cost
Rainbow Beacon = 5,000,000 beacon cost

5 million beacons to create a single expanded beacon? Beacons like this are to be used to advance the game, not be a death march where you finally achieve the goal at/past the end of the game. There should be some pain in reaching the higher performing items, but this is like a Turkish prison beating.

You used to be able to use Productivity modules to get to the final beacon with little effort, but stupid devs "fixed" some crap in 0.16.23, and now recipes that don't accept productivity upgrade won't do it for beacons either. I will now cut down the costs to make them.

get the Beacon Fix 16.23 by anarchyinc, it undoes the "fix" the developers enforced preventing/nerfing productivity modules completely. it makes it so you can actually benefit from productivity modules again.
https://mods.factorio.com/mod/beacon_fix

Now that the productivity applies to everything I think beacons are too cheap. Shouldn't the cost be reverted to those in 1st post?