There are a few things you need to ask yourself when venturing into this hobby/sport.
1. Are you really interested in racing on a club level, maybe at bigger sanctioned events later on once you get a handle on the on-road thing?
2. Do you just want to get your feet wet and see if this is something that can go further?
There isn't nothing wrong with getting into an entry level RTR if you just want to get around the track with a good car, RTR (Serpent) or simply do some parking lot bashing. That's if you truly want to get the feet wet and your really unsure if you are going to continue this amazing hobby/sport in racing these amazing machines with fellow racers and friends. Then the Serpent RTR would probably be the best option for you.
However if you really have your heart set on racing on a club level and you feel you'll have the passion and dedication to get faster, grow with the hobby and continue to race on a club level, also plan on attending bigger races. The RTR isn't the way to go for several reasons......
1. Most RTR kits "DO NOT" come with a legal motor. Such as the most popular class is 17.5T stock (blinky) or mod. So once your around the track a few times your going to replace the motor bringing the car to club specs (more money).
2. Building a "kit" you will learn so much about your car and most importantly, these kits today "DO NOT" need any hop-ups out the box to be competitive (there fast out the box).
3. Buying hop-ups for an RTR is a guaranteed waste of money (if you plan on racing) and aren't as durable as a kit racer
4. Most all RTR kits comes with a very basic transmitter. Almost every RC racer will tell you (if you ask), if you plan on racing, never go cheap on the transmitter.
5. Your still looking at buying the other necessary items for the RTR getting it on the track (charger, lipo battery(s), correct gearing for the track, more than likely the RTR kit tires aren't the correct compound).
The Serpent RTR would probably be your best option if your not wanting to get passionate about racing or being competitive. I started with an RTR kit and went out racing with it. Found it very frustrating and wasted lots of money trying to make the kit competitive. I found the enjoyment came from building my own kit, learning the chassis finer tuning adjustments, choosing my own electronics and making my race car my own as I built it to my liking.
Keep in consideration if your truly wanting to race, save yourself the $450.00 as you will outgrow the RTR shortly after and find the entire RTR kit (car & electronics) useless. There are several extremely competitive kits out there for $400.00 range that are fast out the box, Team Durango has a nice car coming out this month and the parts are fairly inexpensive and will be a mainstream product. Associated has there new car out as well. Yes you'll have to spend more money getting a "kit" race ready, but not much more and you'll save over the long run.
Hope this helps