Well it depends what u want to do with the little car. If u want somethin like i have, which is a 1/10th Serpent Nitro Tourer 4x4, ur lookin new about 600-700 for a rollin chassis plus then 200 for a motor plus then about 400 for radio gear. Maintainance costs vary depending on how well u look after the car and how many barriers and things u hit. Somtimes me and my bro can go to Littlehampton (racetrack) and spend 5 bucks on fuel and about 40 on tyres, this would be an excellent day.
However on the other hand, weve had clutch, gearbox problems, but worst of all, bent chassis and ****ed radio gear, cost about 500 for new stuff.
Also if u have a car like mine they need to be pulled down everytime u start them basically or else the engines dont last long.
In saying that, there was a shop called extreeme hobbies ( i know them they are all wankers) but they sell stuff for beginners to pros.
What i would recomment most prolly is if u want to fang it around, try gettin pull start motor, plus single speed g/box. Also make sure rubber tyres and all that other crap.
I think ive covered the basics
Cya