If you don't need the 18 din, yet you're blowing up 12 / 14 toe pieces, something isn't set up properly. A very small selection of skiers actually need the Pivot 18.
Also, maxing out the din in either direction isn't something I'd recommend either. If you ski at a 12, get the 14. If you ski at a 14, get the 18, etc...don't buy the 14 and crank the dins all the way to the top. Same thing with going maxing out on the low end of the din range.
There's tons of reasons for buying the 12 / 14 over the 18. Buy the binding that is suited for you, not the one that you want to show off in the lift line.
And you get the Pivot 18 for the din, not the toe or the durability.