Don't forget that a new year means new records are available online at Scotland's People. This means that the statutory limitations for release have changed and the following are now available online without the need for ordering the certificates from the GRO:
1911 Births (100 years)
1936 Marriages (75 years)
1961 Deaths (50 years)
Credits can be purchased for £7. This will give you 30 credits or 5 document views (perhaps less if you need to view more than one index) and the credits last for a full year - not that mine ever do!