Cheap O365 subscription recommendation

I want an O365 subscription where I can develop as many intranet sites as I want, with feature publish, and test some apps, as well as have my online SharePoint site as well. What's the best subscription for this purpose?

I can see that all subscriptions include the same thing, so do I get small business with one user? will it contain publishing sites? will I develop apps? is there any other option?

Thanks for the help.