I'd like to post a tweak - I don't think it's been said already, it's not in the list. I think.
Changing Companion Hire Costs:
Find this code:
game_get_join_cost -1
18 21 1 1224979098644774912 2133 2 1224979098644774913 0 4 0 1507 1 1224979098644774912 5 0 2171 2 1224979098644774914 1224979098644774912 2133 2 1224979098644774913 1224979098644774914 2105 2 1224979098644774913 5 2107 2 1224979098644774913 1224979098644774913 2105 2 1224979098644774913 40 2108 2 1224979098644774913 5 4 0 152 1 1224979098644774912 2107 2 1224979098644774913 2 3 0 3 0 2133 2 72057594037927936 1224979098644774913 2075 1 72057594037927936
The formula to get the cost for a companion's hire is:
((X+5)^2+40)/5
The X is the companion's level, the 5 in (X+5) is the first 5 in the code, which is in red. The 40 is the blue 40 in the code, and the last 5 is the green 5 in the code. Theoretically, if you lower the green 5, increase the blue 5, or increase the red 40, the companion's price will increase; if you increase the green 5, decrease the blue 5, or decrease the red 40, the price will decrease. At least, that's what G36E tells me.