The Sukhoi Su-30 and Su-30SM fighters cost Russia $20m a piece by conservative estimates, with some sites quoting double that cost. The Su-24 bomber is an old model from the 70s-90s and the only figure I can find is $25m.

This might have cost Russia $140m minimum in a single strike, not to mention reducing their capability to maintain offensive or defensive actions. They also destroyed more a couple of days ago, also at Saky.

Not shabby.