The present invention provides an automated invoice vetting, negotiation and payment system that automatically collects goods and labors hour data, sets a reasonable pricing structure for each such good and service, dynamically analyzes the price data to adjust for market changes and provides a automatic negotiation and settlement feature for bill payment. The present invention readily accommodates the above features over electronic networks such as the Internet. The present invention therefore provides a method of payment of invoices of vendors by purchasers, comprising providing a settlement authority with invoice information from a vendor, comparing the invoice charges to a predetermined range of values for the charges, accepting the charges that are within a predetermined sub-range for the charges, adjusting the charges that are greater or less than that the predetermined sub-range for the charges and paying the accepted charges and the adjusted charges.