A little late to the party but in regards to pricing I analyzed the cost of all the parts if I purchased separately. The parts he uses are not cheap and was really a significant portion of the price so no I don't think he is overcharging. Owners of SF equipment are lucky to have him around. I did the factory upgrade before I realized Chris was upgrading (or maybe before he started doing it himself) and I noticed a marked improvement. I thought the unmodded unit was absolutely silent but the modded unit was just eerily silent in a good way, I can't imagine his mod being any less dramatic, probably more so because of newer parts that weren't available back when.
