It's like a subscription service for your kid's bike. Nice light weight bikes (Early riders for the balance and 16 inch bike) are available for 5-29 GBP/month. Size up whenever your kids needs a bigger size. The one downside of a quality kids bike is the cost but when you consider these monthly costs...not so bad.
more info: www.hopeacademyuk.com
This is an interesting concept. Besides the upcycle program that Woom does; do you know of anyone in the US doing this?
This guy in Toronto does it… https://www.grobikes.com/
Prevelo also has a trade in plan….