For your first buggy, lots of people here have great things to say about the Hotbodies D8 Hara kit. Definitely race-ready and quite durable. I did up a wishlist on A Main Hobbies to see what a full kit build would cost:
Hot Bodies D8 Hara kit
http://www.amainhobbies.com/product_...tion-Buggy-Kit $400
Werks B6 buggy engine
http://www.amainhobbies.com/product_...tor-Turbo-Plug On sale right now for $190
Werks 2058 pipe
http://www.amainhobbies.com/product_...old-2010-Model $98
Spektrum DX3S radio
http://www.amainhobbies.com/product_...ansmitter-Only $120
Spektrum SR300 receiver
http://www.amainhobbies.com/product_...rface-Receiver $35
Savox 1258TG high-speed servo
http://www.amainhobbies.com/product_...ium-Gear-Servo $70
Savox 1256TG high torque servo
http://www.amainhobbies.com/product_...ium-Gear-Servo $80
OFNA blue starter box
http://www.amainhobbies.com/product_...gy-Starter-Box $95 (yes, it's called a "truggy" box, but it will work on buggies too. On any thread asking about what's the best starter box, this one definitely gets the most votes every time)
The total (not counting taxes) comes out to $979.93 (I rounded up the costs listed earlier). That will give you a very well-equipped buggy. Just an FYI, those servos I listed are not high-voltage servos. So for a battery, your options would be a NiMH hump pack, LiFe pack, or if you wanted to use a LiPo, you'd have to add in a regulator. There are also cheaper options for an engine and pipe. But of course, you get what you pay for, and the Werks engines have a great reputation as a worthy race engine at a decent cost.
As for the Losi 8ight 2.0 rtr buggy, yes it is the best race-capable RTR buggy out there. You get a decent radio, a kit that is good enough for the track and it comes with a starter box. However, to get it truly fit for the track, at the very least, you end up needing to replace the stock servos. That alone costs at least $150. All RTR kits fall under this condition though. RTR kits are designed to get you into the hobby with a fully assembled vehicle, without breaking the bank. So some stuff, the servos in particular, are cheaper and aren't quite up to snuff against "race-level" equipment.