I took the following photo from the Jane Austen Bath Musuem. What a wonderful bit of compartmental "fanancial" information. If you look closely at the photo, there is prime opportunity to survive (albeit comfortably).
Let's explore the income of the Regency / Georgian Era. Take any number that might equate to your annual income... because I was once a teacher, and therefore making an annual income that was laughable, we will be using the annual income of an elementary teacher of the time and multiply this by the number 80. So if a governess made an annual salary of 50 pounds per year, she was doing well.
It has only been brought to my attention from one source that you take any annual income and multiply it by 80, but this seems to make sense with all the ridiculous poverty that one had to contend with!