Everybody would go with price, but as email evolves, even when there have been voices that wanted to bury email for a long time, it continues to be the most used way of communication, invoices, news, family matters, etc are using it and would continue using it in the future…
As per your question, the answer is: it depends.
Perhaps moving to a cloud solution such as Office365 or Google Apps is the best choice for companies that have little or no technical staff on their companies. That is also a plus for big companies that need their IT teams to…