Sensory Equipment for Mason

Well as you know my son Mason has brain damage. He is 18 months but has the development of a 3 month old baby. Well today we went to visit a disabled playgroup where there was a sensory room. Mason doesnt have an interest in toys but today his attention to the lights and colours was something i've never seen him like before, his little face lit up and he concentrated on something for the first time. So i've come home and looked up how much it would be to get some sensory equipment for my little man and to my disappointment it seems expensive. So here I am asking for help yet again. If you can help, I would be grateful for anything. I am really trying to get everything in place for Mason but I'm struggling due to having to give my job up to look after Mason.