We use the SoEzzy spreadsheet as a basis for all we do. Our business starts with our costs, and it has just made sense for us. We also use a CRM software for customer tracking and contact, plus Constant Contact for email. Just exporting data back and forth. You do get what you pay for in the POS/Sales/CRM software arena,and most people never use them to theirfull capacity.
A few no/low cost CRM options here - http://www.top5freeware.com/crm-software-for-windows