I know inflation. 2-3% per annum. So instead of $270 over a couple years it might be around $286.
Also ES has significantly increased. So $COGS per unit might actually go down (buy material cheaper, higher output per cast, mass produce at lower cost per unit).
Nothing to do with inflation.
It is a simple price gouge. It makes sense to do it. Doesn't feel nice for us as customers. If someone's not happy about the $10 that's fine. Just means he's paying attention.
Fact is, SS can charge $400. They can double/triple ES sizes. They can lower QC measures. They can delay production and release dates. Because you'll buy it. But there's a point that you won't. For some people that point is $10 more.
Its simple price elasticity of demand. Right now, SS is ramping up prices to identify the sweet spot where they can max profit per unit and hold supply at a level where output and take-rate will be optimal.
In time, this hobby will get to expensive if SS doesn't watch the market.