I would like a cheap restaurant.
There are ten cheap restaurants in the city; do you have a preference of area or type of cuisine?
I don't care. 
Ask is a nice place, that is in the cheap price range. Is there anything else I can help you with?
Actually, I'd like one in south part of town. Is Ask in the south?
I'm sorry, but Ask is not in the south part of town. There are 2 restaurants in the south part of town and in the cheap price range. Would you like Portuguese or Chinese food?
I have no preference, please make a suggestion. 
nandos is a nice restaurant in the south part of town and in the cheap price range.  Their phone number is 01223 327908 and they are located at Cambridge Leisure Park Clifton Way. 
Okay, that sounds good. Thank you for your help.
your welcome. thank you for calling