For some time, I've been perplexed by the huge price gap between HDTV and EDTV Digital Light Processing (DLP) front projectors. It just never added up that models with Texas Instruments' high-definition 720p (progressive-scan) display chip, most of which cost $8,000 or more, should be priced so much higher than their enhanced-definition cousins costing $1,500 or less.