Depends on your business volume, bookkeeping skills and your
computer skills, I think. Also depends on what operating system you
use. So, what OS do you use? Do you want to do double-entry?
I currently manage my bookeeping on spreadsheets I designed in
OpenOffice. The price (free) is definitely right. I could design a
bookkeeping database in OO Base, but what I have now meets my needs.
There are a lot of free, open-source bookkeeping apps available such
as Gnucash, but which ones are available to you will depend to some
degree on your OS.