Hi Platon, few corrections that are needed in your article

• Azure charges for VMs by the minute — https://weblogs.asp.net/scottgu/windows-azure-announcing-new-dev-test-offering-biztalk-services-ssl-support-with-web-sites-ad-improvements-per-minute-billing
• The 20 VM limit is the default for a new subscription. It can be raised to 10,000 by filing a support ticket.