I’m not sure where you’re located but in Australia I’d def try eBay. You can ususally find 16, 20 and 24kg KB’s for $50-70 plus around $30 P/H which is a lot cheaper than anywhere else I’ve seen. I’m sure eBay in other countries would prove to be similar.
Still a little expensive but well worth it I think as you will have them for ever and they are great fun!
I’ve got a 32kg there too but I don’t seem to use it as often, sometimes for swings and cleans… but maybe you’re alot stronger than me! 😀