Context: As a result of the 2008 Russian military reforms, the units of the Russian Naval Aviation were reorganized into 13 new Naval Air Bases. Each new naval air base consists of an HQ, support units and one or more aviation groups/wings . In a second stage, the air bases were merged into territorially integrated structures. Only the 279th Regiment retained its status. The planned transfer of Naval Aviation assets to the Air Force has been delayed due to their importance to the service, but was finally implemented by the end of 2011. As of 2012, the only fixed wing strike and fighter aircraft of Russian Naval Aviation are the Su-33 fighters and Su-25UTG attack aircraft of the 279th Regiment , plus the Su-24 bombers based in the Crimea. This sole bomber unit remained part of Naval Aviation as an exception to satisfy treaty requirements governing Russian forces deployments on Ukrainian territory . Buying brand new multirole Sukhoi Su-30SM for the Black Sea Fleet to replace Su-24 was in the planning stages and it has been completed as of December 2016. Naval aviation also retains the anti-submarine aircraft of the forces and the helicopter arm. Given the new data from 2015-16 from Russian sources regarding the 100th Shipborne Fighter Aviation Regiment's disbandment in 1993, Air Force's Monthly's listing of both the 100th and 279th Regiments at the Severomorsk-3 NAB has been altered by removal of the 100 KIAP. Naval air bases of the Russian Naval Aviation include: Baltic Fleet air bases - HQ at Kaliningrad:

Question: Which happened first, buying Sukhoi Su-30SM or 100th Shipborne Fighter Aviation Regiment's disbandment?

Answer:
Shipborne Fighter Aviation Regiment's disbandment