1. A method of computer-assisted modeling using a reference price to assist in evaluating discretionary pricing of transactional services provided by a professional, the method comprising: segmenting a universe of pricing episode data of pricing episodes into a plurality of groupings, delimited by at least one price predictive parameter; the pricing episode data including discretionary prices charged for transactional services provided by the professional; arranging the pricing episode data within each grouping according to the discretionary prices; determining a reference price within each grouping based on a predetermined level, rank or percentile; and using the reference price for evaluating the pricing episode data in the grouping.