When the R version was first introduced the upgrade was $500.00. The R version is so much better it is scarry! When people found out how good the R version sounded thet would buy an I version for cheap and send it back for the R upgrade. The cost of $500.00 made the amp a steal and Cary must have thought so too. Not long after that the price of the upgrade went to $1700.00--so I have been told. I owned an I and sold it--auditioned an R version with the oil cap upgrade. In my system, and to my ears it blew away my BAT VK75SE and my Music Reference RM-200, for what thats worth. It's all system, room and ear dependent.
