You are confusing things. A BigDecimal only holds the value of the number; it does not hold a format. So if you do new BigDecimal("3695.00"), you get a BigDecimal object that represents the value 3695.
I guess you have a class that contains a method setNet_Price(BigDecimal price) and a method BigDecimal getNet_Price(). You are calling getNet_Price() somewhere to get the price and put it on screen. In the code where you put it on screen, you need to use a DecimalFormat object with the right format again to format the number into a string, which you put on screen.
Thanks, the place where the value comes back to the Screen is from a context defined BAPI node in SAP WebDynpro application. The table cells themselves are binded to the context nodes. Not sure how I will format the value there, and I suppose that is a SAP forum question. Thanks again for all the replies!