How would you price this aggregate and limestone?

Ok, I’m trying not to repeat my mistakes from the last job, so I’m asking for some input on this one before i quote it. I got some well-deserved criticism from some people on my approach before, so i want to do this one right.

the customer has limestone with black mildew spots. i don’t know if it’s sealed, and the planters have a pretty rough texture. the walkway is made up of aggregate slabs with soft flexible expansion joints. i would say it’s about 400 square feet of aggregate and 200 of limestone. i’m not sure about using a surface cleaner on those soft joints…

has anyone used prosoco limestone restorer? i have a buddy who used it on a big job and got nice results. would that be an appropriate product for the limestone on this job?

I reiterate what I said last time that I would do a couple of test spots with housewash up to roof mix. If it doesn’t come off easy, walk away.

I still walk away some and I half way know what I’m doing.