Help me understand why Yellow Beachhead are more expensive then red?

I have only 1 Tier 10 (yellow) The Beachhead Harbinger Map:



I want to do it alone for my first experience to unlock the 1% bonus map completion on Atlas. But the price i see on it is insane:

Searching on trade (in standard) i see the following prices:

-the white version (tier 5) of Beachhead costs >1 Exalt
-the yellow version (tier 10) of Beachhead costs >10 Exalt (up to 1 mirror)
-the red version (tier 15) of Beachhead costs >135 chaos

Why would the yellow version be so much more expensive then the red? I know people are doing rotas for experience but since i will be doing it alone would a red version be more beneficial? I'm lvl 96 at 0% exp. I mostly want to do it with good drops for my first experience not for exp.

Do i need to apply a Harbinger's Orb on to make it red? If yes would it then be more beneficial to sell it for > 10 exalts as yellow and just buy a cheaper red version of it and run that one instead? (since the price on yellow is insane).

The prices make me very confused.

Also what else do i need to run it with? I'm assuming 3 sacrificial fragments for extra quantity. Scarabs don't think will work on unique maps. I don't see Beachhead on Atlas so i'm assuming i can't use Sextants either. Am i missing anything else?

Dunno where you get your prices from, I see t10 yellow Beachheads being sold in Blight SC for 2 Divine Orbs.

The Beachhead does not give 1% Atlas bonus. It is, I believe, part of the Blight League Challenges, for this the tier doesn't matter.

You cannot change the tier/colour of a Beachhead map.

This are the only prices for them in standard:

http://poe.trade/search/hiarasitakinok

From 10 exalts to 1 mirror. Are they fake?

Right, Standard league then, turn off your online filter and you will see them being sold from 45 Chaos (two weeks old), though around 100 Chaos being more realistic when judging by recent offers (98c yesterday).

But again, the map is not part of the Atlas of the World, no bonus here. Just run the map for the fun of it but don't get your hopes up too high regarding loot. If you want decent shard loot run t15 Beachheads with lotsa IIQ. If you plan on exping fast in t15 Beachhead, ask for rotas in global 820, this way you get 6 runs per one of your maps, this will keep the costs at bay.