Here's the situation: My dad's decided I'm not allowed to build myself a PC and I've instead got to get a local PC shop to build it or buy a prebuilt (He'd prefer the second, my bank account prefers the first or building it myself). As you've probably seen I've got a system specced up on ebuyer and ready to be bought, I just need the parts to arrive in order to build the beast. The local PC shop is saying they'll charge £30 to assemble the rig himself, however I believe his knowledge may be rather limited when it comes to computers, this is based on him saying I'd need an 850w PSU to power the system in my sig, despite my having been told repeatedly I need nothing of the sort even if I want to crossfire 2 4850s, he's basing that on his system running an 8800gtx on a 1.3kw PSU. So, here's the problem I'm not entirely confident in giving all my parts to him since he sounds like a PC muppet. If I order the parts today or tomorow I may be able to assemble the system on monday and get some serious gaming in that night (I have the day off school). So, how do you guys think I should persuade my dad to let me build the machine?