Visualize Jira data with Grafana with no cost plugins or software

Jira data is easily exposed, but to convert it to Grafana-suitable data easily, your best option is to find or write  some "expensive add-ons, gadgets or plugins".

You are going to find that writing them for yourself is the best option, because you can make them do *exactly* what you need, but it's going to be a lot faster and cheaper to go for apps that do most of what you need.