I don’t want to get into details here but does anyone know where I can buy a complete kit with electronics for building a quadqopter?
Hobby king would most likely be your best bet.
@Craig_Blanchette can’t find any complete kits there…
I think you can get all the parts needed at http://store.3drobotics.com/t/diy-kits/arducopter . It doesn’t look like they sell it all as a package, but poke around in there…
If low cost is the key, you probably wont find a kit.
If you just want to avoid the hassle and pay for easy there are more options. AR drones are nice.
AR drone is a complete kit among many (DJI, for example). This is a classis build vs buy question. How much can you build? What % ?
Yeah, it comes down to: you want RTR or ARTR?
I want the electronics, I want to do the rest on my own!
In that case, why not pick up the electronics from 3D Robotics, or one of the clones 
3D Robotics is the real deal. These guys (below) is the factory shadow shifts. You get what you pay for:
http://rctimer.com/index.php?gOo=goods_search_list.dwt&gcat=206
Goodluckbuy dot com has a good range. (Yes it does look like a dodgy name)
Good luck when you buy from http://goodluckbuy.com
Yeah the name makes you think that but there well respected in the quad copter community.
I’ve heard of many horror stories with botched shipping, bad packaging and things along that line from goodluckbuy