maybe try this
Go to you local track, talk with the people there. Get a feel for which drivers are friendly,outgoing and potentially helpful to a newcomer.
Go back to those guys and tell them you are looking to buy new car and ask them if they might have one to sell. Hopefully you will find someone who is looking to upgrade and you can buy their old car with spare parts at a reasonable price. Most likely the car will be fine tuned for that track, you will get the spare parts virtually for free and their will be someone you can go to if you have problems who will be very familiar with your car.
Make sure you have a list of current models and a rough idea of previous models, Associated TC3,TC4,TC5 Xray T1,T2, 2005 2008 2009 to cover the odd chance that someone may try and pull a fast one and dump a very old model on you, When in doubt just ask here on this forum.
If no second hand car is available then see which chassis is most common among the local racers it is that chassis you will be able to get the most good advice and help with.
Also, both X-ray and Cyclone make sub-$200 models which substitute durable plastic chassis for graphite fiber ones but share most of the same suspension and drive train parts.