I thought the prices of housing were absolutely crazy when the patch first hit but now I don't think it is such an incredible hurdle.
Depending on your FC size it is incredibly easy to raise money for a house and you only have to do one activity - Treasure Hunting
My FC is only around 10 people but 2-3 times a week we go out and do Peisteskin Treasure Maps as a group.
- Maps spawn on level 50 gathering nodes with an 18hr cooldown (1 per day basically)
- You can only decipher one map and hold 1 other so you may need to mail them to a designated member to hold them all
Each member in the party gets Gil for each map either ~1600 or ~5000 and random crafting, shards, and sometimes drops (mid 40s armor, crafting, minions)
We do 2-3 maps each, takes around 1 hour and yields between 300 and 400k just in Gil that we throw in the bank. We also have members throw the HQ materials and any good crafting drops in the bank to sell as well which usually nets 50-100k per evening.
We have gotten rare minions as well which sold for ~1 million on market.
So my tiny FC with only 8 people spending 3 hours a week working on this gets ~1 - 1.5 million gil towards our house.
We didn't start doing this until a week after the patch hit but we have already raised over 3 million Gil from treasure hunting.
Multiply this for FCs with > 100 people and you can see the incredible amount of money this is pulling into the economy and the reasoning behind the insane prices.