I guess it depends at what level & where you want to race at & your budget...
If your on a tight budget (say £250) a Durango DEX210 RTR, set of tyres, mid motor parts & a LiPo & charger can be had all brand new from UK shops...
Or a good used set up of a (not the latest) buggy can be had for around that. B4.2, Losi 22, DEX210, Centro C4.1, Cougar SV1/2, etc...
If you want to race competitively & buy new then I guess about £500 will get you a latest generation 2wd chassis (B5m, Losi 22 2.0, DEX210v2, Cougar KF, etc) & some decent electrics (Hobbywing, Speed Passion ESC/Motor, Savox servo, SMC LiPo) & a few sets of wheels & tyres...
If you race on high grip surfaces such as Astro or carpet then a mid motor car will be the way to go. As others will no doubt tell you - go along to a club & see what others are running.
And always look at the signature at the bottom of someones post when they tell you a specific brand of car
