Sorry no experience as an employee and the amount depends on your local prices. You could look at the employment ads. But remember : an employer will look for your level in pure Android and probably won't accept you to code in B4A.
He would probably ask you to use Eclipse or Android Studio and not B4A. Not because B4A is not good but because you could be in the grid of your job.
You could have more luck as an Indy because indies clients only care about the result and not the way you do things. They buy a final and don't care if you are replaceable or not.