I was hoping that I could build my own at, or even below, the cost of the RTR. Now, with the cheapest electronics and motor I can get my hands on, maybe, but to meet minimum specs of what I want, I just can't beat the economies of scale that a manufacturer has. The RTR sells for about $336 right now, and I figured I was good if I could build my version for about $400 net. My math is making some assumptions and massaging the numbers a little bit, but right now I am $437 gross out, but I am thinking I came regain that some and tweak a little.
So, the base to start with is a DR10 kit. They are available on Amazon for $124. The DR10/RB10/SR10 are very similar in most ways, with each having some specific parts. Remember if you are parts shopping is that the RB10 is a current release model, so there are "choppers" on ebay breaking these down and selling off parts new but cheaper than retail (although check retail prices anyway). The main things needed to add to the DR10 kit is RB/SR chassis, RB/SR shock towers, and of course wheels/tires (which can be any buggy 2.2 12mm hex variety you like). I just stuck with stock RB10 wheels/tires, and my total cost for chassis/towers/and wheels/tires was about $86. The fronts shocks on the DR are also too long, so you need some RB fronts for about $30. This is where I start to massage the math, because although I had to buy front shocks, I will ultimately use the DR front shocks in the future on another project, so I don't mind calling that $30 a wash.
TX/RX and servo can be whatever you like. I use a multi-vehicle Tx so I just need to add a cheap Rx. I have a cheap servo that I also like. Total Rx/servo cost about $36.
For motor / ESC, I went with what I believe is the cheapest 3300kv sensored set up you can get from Hobbywing (10BL60 sensored & EZrun3300kv), for about $78 total. **CORRECTION: the EZRun 3652 is not sensored. It has a temp sensor and port that I mistook for a sensor connection**
That is the basics for the mechanical parts to get you going. There are a few small bits that I already know are different, and may or may not be needed, but I will discuss them through the build.
First pic has nothing really to do with this build, just something new I have been trying ............... organization! A little prep work really does save a lot of time in the build.
The actual build is just building a typical AE 2wd buggie for the most part. I am building using the RB10 assembly instructions as reference, and using the DR10 parts mostly and just adding in the RB parts as they are applicable.
The RB apparently uses angled ball cups on the steering outers according the manual, although the part number is the same as the other ball cups. The DR kit only comes with straight cups. It seems to have plenty of steering with the straight cups, but maybe these are needed in the long run for the most steering, who knows.
I didn't have the 3mm CS 16mm screws to attached the rear shock towers to the rear posts in my kit (at least not in the bags used to far), and these show up in both the DR and RB assembly instructions, so maybe just a kit error. Not an issue, have plenty of 3mm hardware around.
You will be missing a spacer used on the RB between two mounts on the rear bumper. On the DR, a body post uses up the space, but without the post, there is nothing. I don't see any reason to go out of the way to put a spacer here.
All was going smashingly so far, until I went to install the rear turnbuckles, and the driveshaft wouldn't go into the trans outdrive on one side for some reason. It appears the be just a completely mis-machined outdrive, not having the tapered lip, and the inside diameter is only 5mm instead of the 6mm needed. I am hoping I can "machine" this tomorrow, as I don't want to put this project on hold for a few days.
The body came from a repop shop in the UK, and to be honest, after comparing it to a Boki Protech, the quality was simply not as good, and that is why it was chosen for this runner instead of a nicer future build. The wing is the same ~1.0mm as the stock (and Boki) wing, but the exact PC seems to be much more rigid, and I really had to torque on that thing to bend it far enough to insert the wire, and then I was gouging the wing with wire, and it was just a PITA. I figured after painting, if I tried to mount it all with the front edge, it would have been a mess. I probably could have spent a few minutes and come up with a rational plan to get this done correctly, but the idea of it being a yard basher popped in my head and just cutting the obstacle out of the way seemed the easier way. It wasn't the right way, but it was the way right then. 
