I would upgrade to a 2x2x4' mesh cage. Order one for around 110$ from lllreptiles or diycages (or other companies).
I would not buy a bgrade cage because while 70% of the time they only have teensy flaws for only 50$ sometimes they are unusable and you have wasted 50$.
I you can go for a 2x2x4 cage from muji chameleonworld seeing as you are in the uk. They do great drainage bases with them too. If you want something cheaper the Xl reptibreeze from Essex reptile is a great choice.