Screaming Penguin - Source Does Matter

Newsforge has a great "real world" review of a Linux Canada product called Quasar. Quasar is a small business accounting and POS package for Linux. Quasar sounds like it has all the features, accounting, invoices, etc, etc, etc. The "base" package is free for a single user and for networked concurrent usage it costs 29 bucks per. There is also a "whole deal" package with a database backend for $400 bucks.

I havent checked it out personally yet, but it sounds like it is worth a look.

For more info see the link -------->   Quasar Small Business Accounting Software for Linux: NewsForge