A complete newbie should by RTR. First, most people are impatient and want to get right out and drive. Second, you will quickly find out if you even like the hobby and working on the car. Everyone knows RC is 75% wrenching and 25% driving. LOL.

Once they get tired of the RTR they will automatically want a kit. The other thing to keep in mind is that most newbs don't have the proper tools to effectively build a kit without having to constantly make trips to the LHS.

Once you have been in it a while, building a kit becomes second nature and you wouldn't want it any other way. However, starting off, building a kit and not knowing all the things you realyl need to get the car out and drive just serves to frustrate potential hobbyist.