sorry to bud in.. maybe I can help explain..
The .psd files are great for anyone, because it saves time. On the standard version you would have to upload all your image files somewhere, modify them individually, then save them over the existing images, upload them ect.. Which usually takes a lot of time. As a developer, time is money.. .psd files come very handy, because all the line margins, colour settings, and size are already there, ready to open in PhotoShop and let the creative juices flow.. then save and upload. For the extra price it's defiantly a plus, especially when designers pop out websites every day like clock work. Comes handy. Anyways.. my 2 cent.. keep up the good work guys.