Plasma Televisions were designed for the purpose of replacing large screen televisions (specifically going after the rear projection television market) and their production and marketing emphasis reflects that goal. However, in larger screen sizes, LCD televisions are more expensive to produce than Plasma televisions (although this difference is narrowing due to advancing production techniques).
As a result, large screen LCD TVs usually command higher prices in the marketplace. Although you are seeing many affordable ($1,000 and under 32 and 37-inch sets), and ($1,500 and under 40 and 42-inch) LCD televisions saturating the market, the prices of larger LCD televisions (46-inches and up) can be more expensive than their Plasma counterparts, although the price difference is narrowing quickly.
As the flat panel television market stands now, Plasma televisions currently dominate the 50-inch and above sizes, LCD dominates the 40-inch and below sizes, and both LCD and Plasma are in parity in the 42-inch screen size. However, LCD has recently been making strides in the 42-inch and larger size range and is rapidly catching up to Plasma in the 46-inch size range and larger, especially as the number of manufacturers of Plasma Televisions keep dwindling.
Currently, the largest LCD TVs available to the general consumer are in the 65-inch screen size, while some plasma screen sizes have reached 70-plus inches, with the largest Plasma television available for sale for commercial purposes currently is a 103 inch model from Panasonic's Business Division.
As technology develops increased production efficiency, supply, and demand continue to grow for LCD, you will see an increased availability of larger screen LCD televisions (42-inches and larger), as well as more affordable price ranges for even larger sized LCD TVs.