Pool Deck Repair Estimate

I need some advice or feedback on what it should cost to do a repair (as pictured) on a portion of my pool deck. I don't know the exact square footage but it's not huge....a guy came over today and quoted me $600. I live in Las Vegas. Since I've never priced this type of repair before, I have no idea....am gonna get a few more estimates. But wanted to run it past some of the experienced people here who know more about this type of thing. I don't want to get ripped off for a fairly small job. I realize that those individual bad areas can't be simply patched because there's "hollow" sounds when some of the surrounding area is tapped, so I know this basic section has to be scraped up and re-coated. I realize it's somewhat hard to tell from the photos how much the area covers. The dark lines you see are overhead power lines (sorry!). This is an older pool, built in the 70's, and the deck is holding up semi okay, but this one section has started to really need repair. I don't want to do more than absolutely necessary, with the housing market the way it is out here, overspending on stuff is definitely not gonna bring back any huge returns, so I spend my money wisely and make repairs as needed and only as absolutely necessary. So, $600? Good, bad, or overpriced for a moderately, not huge job (area wise). He says he can get the stuff to match what's on there, to match the rest of the patio. Thanks again!