Fabric scraps can be repurposed
Now, this hack requires extra skill, and that is sewing. Nevertheless, it is not complicated to put together, and even someone with a basic level of experience could pull it off. We are talking about making coasters out of fabric scraps, which are usually sold for very little or given away for free.
First, cut two fabric five-inch by five-inch squares per coaster and pin a bottom and a top piece together by the right sides. Then, stitch around the edges of the square, leaving a two-inch hole. Turn the coaster right side out from the hole, tuck the edges in, and press it. To finish it, close up the gap.