We’re selling this excellent backpack infant carrier for $60. It’s for kids 18 months to 3 years, but as it’s also safe for weights up to 18kg you can carry older children in it too (I had my almost 5 year old in it recently).
It’s brilliant for when you want to walk somewhere you can’t push a buggy e.g. woodland walks, supermarket visits, or when there’s deeper snow on the ground. It’s got a large pocket that can hold a surprisingly large amount of groceries as well as straps you can hang things on. Honestly, I’m sorry to part with it but my kids have (almost) outgrown its utility for us.