Dear Sir,
I have very good knowledge and experience of developing Accounting system including double entry system. I can provide you a system that will be capable of raising vouchers and posting Journal entries, doing a trial balance, and generate annexures for the preparation of balance sheet. The package can also have a integrated salary module so that all components of salary too be a posted to the Accounting system. But the bid amount restriction of 100$ is very less. I feel in oreder to get a customised accounting system software, the good price will be around 1000-1500USD depending on the exact requirements you want within the package. Please do PMB me if any further details are required.