I will make an accountancy software which will write/read datas to/from MySQL DB. It will only use one table and will make some mathematical count with these datas. For example it will count the taxes etc...

How much price shall I demand for such a software's source codes? ( user will get all codes for the software)
and
How much price shall I demand for such a software's setup? ( user will only have the compiled version and a serial key for the software)