Maybe the tuners are using the rarity to jack up the prices, but this is entirely reasonable. The fewer number of potenital customers you have for something, the higher the price to get the same return. A turbo kit isn't something you just whip together. It takes some R&D, and the cost of that has to go in somewhere. Maybe, when there are as many 2.5's on the road as there are civics, the prices will come down.