When people hear of $100+ dollars per foot for polishing ... they seldom factor in that fact that it can cost up to $400+/- in supplies to do it right.
At the very least~ Plus, don't forget the man hours involved~!!
But then, You knew that`
I have to agree, it's a super nice looking job~
My personal take on the upkeep is:
It's gonna be (at the very least) a semi-annual thing. But, it'll be nowhere as much work as the initial stages of polishing.
With the right tools and polishing compound..
I'm gonna guess a weekend?
The reason is...you're beyond the learning curve.