pos software with complete Accounts

Hello, I would like a Point Of Sale system (source code delivered). The software is targetted to be sold with various businesses like local shops, pharmacies, clothing outlets etc. Please et me know if you have ever developed such a system. The system should be deveoped preferrably on ASP.Net / C# and SQ Server/Oracle . In short, I should not have to worry about buying licenses etc. It shoud also be easily installed on Personal Computers. Besides of managing the stock of items, I would like the system to support LIFO, FIFO and average price for buying price, management of expiry dates of items etc. It should support at least barcode scanners and POS thermal printers. Hoping to hear positive replies. If you have done such system before,