The breakdown of the economy in the world is simple. Money runs everything. From allowing you to preform research, to allowing one to purchase gear or transportation. There are a few ways to make money, but the most common and easily the best option for those aspiring alchemists out there, is to join the military and gain pay based on your rank bracket.
In Amestris and all over the world, the currency is known as "Cenz". In the anime/manga, we are given very few official numbers to transactions, but we will use what we know, compare it to the real world and see what we can come up with.
Basic Weaponry- (Swords, Knives, Armor, Clothing)- 5,000 Cenz
Advanced Weaponry- (Pistols, Rifles, Grenades)- 10,000 Cenz
Automail- (Any Limbs)- 1,000,000 Cenz
Transportation- (Trains, Planes, Automobiles)- 1,000 Cenz- One Way
Now, to break down the attainment of Cenz, one may make some money preforming aid to their fellow citizens of Amestris, Gambling at the casinos in any major city or by being in the state alchemist program.
Jobs taken from citizens pay based on what you agree to from that player, so can range to any amount really.
Casino's will be broken down once we add them in their own sections.
As for military pay, its broken down into a weekly pay basis where you must claim your pay once per week. If you forget, that pay is forfeit, so make sure to remind yourself. It will be broken down as follows.
E-Bracket- 10,000 cenz
D-Bracket- 25,000 cenz
C-Bracket- 50,000 cenz
B-Bracket- 250,000 cenz
A-Bracket- 500,000 cenz
S-Bracket- 1,000,000 cenz
SS-Bracket- 2,000,000 cenz