Earn a total of 50,000 livres.

In order to get this achievement you must earn 50,000 livres.

1. There are many ways in which you can make money in AC5, one of the best ways is through Cafe Theatre, by renovating this is will get you coins on a regular basis. It will cost you money but it will gain back well more than you invest.
2. Another way to get money is play missions, some co-op missions can pay up to 25,000 per play and normal missions can pay up to 2000 which will get you some of the way.
3. There are also Paris storys that have large cash rewards although some of these can be quite time consuming.

In short the best way to make money to get this achievement is through Cafe theatre.

Set some time aside to get a large chunk of your money.
You can get this achievement by just leaving your xbox on and reaping the rewards of the Theatre. As the money is put in on a time basis.

This video show you how to make money in assassins creed and will help you in getting this achievement.

If you need any help feel free to PM Me.