How to make gil for your FC House

[Sylkis]

The person buying the map will still generate the gil you aren't

This is what I was going to say. Somebody will eventually use the map to generate gil.

Right now, maps are about 10k on my server yet I am still simply selling them because they are not worth the time.
To get the max amount of gil you have to party with 8 others and each of them would have a map (otherwise you only get 1.8k back).
Doing 8 maps takes about an hour, which gets you about 15k gil (not including items).
In that hour I could have sold the map for 10k, farm something else and easily make more than 5k.