Jared’s answer to “WHY WHY WHY - Why are the Weasley's poor? Arthur has a job at the ministry, Molly could easily get …” > Likes and Comments

Food can't be created, but they can multiply it. When Harry, Ron, and Hermione were camping, and they stole fish and other food, Ron was saying there was no point multiplying it because it was disgusting. Also, Charlie and Bill didn't live with them. Also - Why would Molly buy new robes for ron is he could have his brothers old ones? There was no heating or gas to pay for as well...

You’re right. We can add it to the list of plot holes