The pic isn't the best, but I'm no photographer, lol. It looks crooked in the pic for some reason, but doesn't irl. And that is only some of our pieces. This was actually really cheap and easy to make. Did I mention fun?
It measures 50" x 30". This could definitely be done on a much smaller scale and still be fun. I've seen people use cereal boxes or gift boxes too. They covered the boxes and stored the pieces inside. The cardboard was free. We bought spray adhesive and 1 yd of felt. The felt I lucked into getting for $3 on sale at Jo-Ann's. I also used fabric glue I already had to secure the felt all around the back. Dp used some screws and washers he had to hang it up, but it could have been done differently I'm sure. I think some people buy a frame for it. He wanted it to be really secure and immovable because youngest dd is 16 months old. I have it in my head to make a felt border around the edges at some point to cover up the screws. So maybe $12 worth of materials altogether? The felt pieces you could buy or make yourself. I've probably spent about $15 on felt, but have a ton left still. For the pieces I used templates from the internet and some from library books. Some people use coloring books or make them themselves too. I can share sites or books if you are interested. My older dd, 9, also had fun making pieces too. You can use the fabric glue to add small details with contrasting felt or material. Your dd could probably help you design a few that way, if you cut out the pieces. I plan on making more food and shape pieces, animals, some fairies, trees, gnomes, and bushes, etc, and possibly an alphabet and numbers, also some fraction and decimal pieces for the older kids. I'm also considering making a busy book with the felt. Yeah, I've got high hopes! The older kids wanted people and I've made a few with limited success, lol. I think people also use them as story boards, like tell a specific story while moving related pieces on the board. I can see youngest dd maybe liking that when she is a little older.