it depends upon the preservatives. blood can be preserved for thirty five days(by using preservatives)
I have heard from the Red Cross that it can only be kept for 45 days, but is usually used long before then.
I think its by blood type cause if they mix diff. blood types, it should not be given to a person
You pay for each pint. Ask the blood bank for specific rates.
The donated blood is kept in a freezing storage.