What are you looking to do with it? Race? Bash? A mix of the 2?
If you plan to race, the only RTR I would even recommend is the Losi 8ight-T 2.0 RTR. It's got everything you need to get started except fuel I believe.
Other than that...I would buy a kit and all your electronics seperately since you can get better quality items that way. Personally, I'm going to be buying a Hot Bodies D8T Truggy kit within the next week or so. A Main has them for $329.99 and a $25 coupon to use....so for @ $325 you get a brand new kit sent to your door.
Then you need:
Engine: $100 - $500
Servos: $100 - $250 for both
Radio: $100 - $400
Bump Box: $50 used, or @ $150 new (OFNA Truggy Box)
Batteries: $50
Charger: $50 - $200
So a lot of it depends on what YOU want for equipment, rather than what they include in an RTR. I'd rather pay $100 for a good servo, than $60 for one I will replace with a $100 one in 6 months time. Saves me $60 ;-)
It might cost you $100 or so more than the Losi RTR depending on what components you pick, but in the end...it's an extra $100 well spent if you plan to race.