The Price of Lippage
This is the price you pay for "lippage". Lippage is when tile are not set flush to each other. If you've got a natural stone floor, it can often be ground flush and polished, but if you've got tile, no such luck.
Yes, these tile can be replaced, but I can't guarantee I can eliminate the lippage without removing the adjacent tile and I can't guarantee I can remove the lippage from them, so when does it end? The adjacent tile dictates the placement of the replacement tile.
Yeah, I know your old uncle Guido could lay dead flat tile by eye. Unfortunately, an illegal alien has replaced him and since he's getting paid by the square foot instead of the hour, the faster he goes, the more money he makes. In combination with customer greed for the lowest price, this creates a huge conflict of interest. Depending on the tile, this probably won't be noticed until the check has cleared.
You can stare at the chipped tiles for a decade or so and have the price of a replacement floor, 20K, deducted from the sale price of your home, that's what this homeowner chose, or you can have replacements installed for 10% of that and hope the buyer's inspector doesn't notice the match of the replacement tile and grout.
The saddest thing is that this is completely avoidable with modern tile leveling systems:
Here is a link that might be useful: Raimondi