Budget wise as little as possible but seriously i think 400 would be ok. Could stretch to 550 tops i think.
Theres a fantastic eos700d bundle on ebay with 18-55 and 100-300 lens with two tripods and about 20 other accessories on the bay for 550ish, all brand new.
Seems a good deal? That way i could take better photos at f1 than the nx30? and have a brilliant everyday camera and landscapes / portraits etc. First landscape shoot will be iceland.