Hi All,
Just to highlight some things here. Please do note that for Azerbaijan, Belarus and Georgia we can take visa upon arrival but for that we should have an invitation letter approved by the ministry of foreign affairs of the country to be visited. An alternative is to have a touristic voucher from a ministry approved tourism company. In any case, if these documents are not already taken prior to travel, visa will not be issued upon arrival and you will be deported.
For Azerbaijan, the cost of ministry approved invitation letter for Pakistani's is around 400 Euro and visa fee is 50$ for 7 days visa (which is max. duration issued upon arrival).
For Belarus also the cost of touristic voucher is around 300$. I am frequent traveler to both places so I am giving this information from my own personal experiences.
For some reason, all ex soviet states have very strange visa policies and its esp. pretty tough and expensive for Pakistanis.