The simplest ceramic fish plates cost around $15 each and It goes from there. The price varies greatly on size, quality, design or details, and brand. If you are looking into filling an entire wall with designer ceramic fish plates, then be prepared to splurge.
If you are decorating on a tight budget, remember that it is not about being cheap or finding cheap items. Instead, it is about being smart and making an informed buying decision. Get the most bang for your buck with each ceramic fish plate that you get.