You can definitely get a pretty good machine in that budget. Most of the new riders who go for 250 look for brands like CBR of Honda and FZR of Yamaha or ZXR of Kawasaki, old models of these bikes are still on the roads in big number. The qualities of a good engine, cosmetic condition and legal status does not come with many bikes, which is quite unfortunate.
One more thing, a sports bike is for performance. Economy and performance are two opposites in the bikes you are looking for. For economy buy a CD70, for performance, looks and all that get any sport bike of your choice. I hope that makes sense.
If you buy from any showroom you will be paying at least 50k more than actual price, and if you buy from some owner make sure the documents are transferred in his name and the engine is in good condition. Normally the engine's sound will tell a lot about it.