feeder cities

so how do feeder cities work now? I read the post that gets linked when people ask this but it's 9 years old. I made a city today w intention of it being a feeder for manufactured resources but then I remembered there's minimum that you can sell things for on the market. my original intention was to visit my feeder city on my main account, put resources up for sale on my feeder for $1, and then purchase it immediately on my main. but now I'm realizing it's not an option. can I get an in depth up to date understanding of what people are using feeder cities for now? thank you!!!!