I highly reccomend buying the kit. I've only been into RC's for a few months, and I haven't had any trouble with it so far. I have to credit where it's due, HPI did an surprisingly good job with this kit. The instructions are VERY easy to read, and the parts for each step are in a differernt bag so there's no guess work as far as figuring out what screw to use and that kind of stuff. The quality is superb, a lot of the screws on my T-Maxx are already rounded out, and I haven't stripped one on this Savage.
If you buy the kit, you will need to buy the radio equipment, which is the transmitter and receiver, and the servos. It has a pull start, so if you want you can add the Roto-Start fairly cheap. I bought the radio equipment from Rolex for $25 , and I got some pretty good servos both for $50. You will also need fuel and a glow-plug igniter, but you'll need that with any RC.
The kit has a lof of upgrades such as many steel gears instead of plastic, it's got a bigger carb, I think it has better wheels and tires, steel spur gear, stuff like that.
I can't say it enough, I would recommend this kit to someone just getting into RC, and if I remember correctly you have been into electrics before. I can't think of a better way for you to learn about a nitro vehicle. I bought the radio gear from someone that had bought a RTR version of the Savage and used upgraded radio gear, so I got all the electronics except the servo brand new for $25. I think when all is said and done I will have about 12 hours in the entire build.
I bought mine from Debbies RC using Ebay. I paid $360 I believe and they had free shipping, but it might have been $369, something like that. I used Debbies RC because they are an established company with a big presense in the RC world, and my truck came super fast and it was the best deal I could find. Everything still had the HPI factory seal in place so I knew it hadn't been tampered with.
I hope this helps in your decision.