In a Press Release published by HWinsights, analysis of the list price at launch and overall usage for the Intel HEDT platform since Nehalen points out that PC DIY enthusiasts are willing to spend a premium on products with the right features. Two of the most valuable CPUs, the Core i7 980X (Intel's first six core consumer processor) and the Core i7 5960X (Intel's first eight core consumer processor), were both listed at the USD $1,000 mark at launch.
Interestingly, the Core i7 920 processor was very profitable in terms of launch price and consumer adoption. The Core i7 920 is the most affordable variant of the Nehalem architecture launched at the end of 2008. It features four cores and a completely new architecture. It was the first of many quad core Core i7 products in the HEDT space and does remarkably better than all of its successors: the Core i7 3820 and Core i7 4820K. The new Core i7 5820K is the first six core processor product below USD $400, which may explain its popularity.
Long story short: Core i7 920 and Core i7 980X were very popular; only the recently released Core i7 5960X comes close to its performance in the market.