Because of the size, I can't get this any cheaper to be printed with Shapeways. Sorry about that! You can always print your own for free if you have a large format FDM machine if you go to micahbot.com
I wish I could get this price down lower without sacrificing the strength of the shelf because these shelves have provided me with more personal joy than I could ever have anticipated! My cat is super cute, but these shelves somehow magnify her cuteness tenfold. Some cats are "tree cats" and some are "bush cats". My cat is a tree cat and loves to be up high, looking down at us with imperious contempt. She now spends most of the day on these shelves and it's really great for when people come over since she feels like she can get up high to escape any unwanted affections brought on by her ridiculous cuteness. ANYWAY... this is my shelf and I love it, but it'll cost you.
Please note that my cat weighs 7 lbs so she's tiny. The shelf is strong so it's not so much about the weight, but whether your cat would fit on the shelf. I think the shelf should work for cats ups to 10 lbs. Also, you will need to get some carpet of your choice and adhere it to the top of the shelf. Bath mats also work well, or you can get smaller pieces of carpet, or carpet samples from hardware stores. To adhere it in place, you can use actual carpet tape, or 3M foam strips, or whatever you have lying around-- it won't need a ton of sticking power since the shelf is designed with a recessed area for the carpet, it just needs something to keep it from sliding around. Once the shelf is mounted, you can fill the screw holes with white silicone cauk.