Over the long haul, yes, but in real-time - no. And electricity prices to fluctuate a lot over days, weeks etc..
But indicating that 'price stability' is a point for green is not really fair, when it's almost always going to be considerably more expensive.
Knowing that something is going to be 'consistent, and consistently more expensive', I don't think is a good argument for green.
There are other, better arguments.