I have developed my website, which uses SQL Server 2012. According to your comparison tables, only the Max package includes the Attach MDF File Tool. How else would I be able to copy my database to your servers if I don't opt for the Max package? Also, if I go for one of the cheaper packages and later i want to upgrade then what can I do?
You could backup and restore. Those tools are available on the Basic plan. If you want to upgrade/downgrade your plan, please follow these instructions.