It depends on how far you want to walk - we recently went to the Dukes Head at Wallington Green. About £25 per head for 2 courses (lunch). Food was excellent. There's a separate bar menu which think is cheaper. Also Italian (was Gustos, now Al Verde on the corner at Wrythe Green Lane (near petrol station). Extremely friendly and food is good. Both these have excellent reviews. Hope this helps!
I'd say The Hope, Carshalton (West Street). Very decent food and it won't break the bank! Also, an excellent range of beers from the bar. It tends to get quite busy on weekends though.
Thanks everyone who replied here or on the facebook page:
Hope, Sun, Duke's Head, Al Verde, Koryocos and El Nido - all look good!