I'm completely failing to remember where I read this, but someone once posted a spin on draconic greed that I liked.

A dragon does not care about what mortal's value. A quartz and a diamond are both shiny rocks to them. Rather, they care about what the object is worth to the person who possesses it. A dragon might lay waste to a king's castle and make off with treasure and princess. Or it might find a beggar and take his worn shoes, his ragged clothes, his walking staff, the two copper pieces in his belt. The dragon ascribes equal value to both sets of treasure, because he has taken what they value most from both of them.

If you want to scare your players with mechanics, I don't think dragons need any particular buffs. Sorcerer spellcasting is quite good, and most of the standard stuff applies there. Just remember to play the dragon smart. A dragon should always be fighting on the ground of it's choice, between it's spellcasting and it's own mobility. It's lair in particular should have years or decades worth of work put into trapping, warding, and shaping. Tucker's Kobolds with giant lizards, basically.