I don’t understand why any buyer in the right mind would want to do this. $700k with a 60k cash back (even if legal) means you would end up paying for higher property tax than you would need to. Of course you could reassess your property tax. But then you are subject reappraisal at any later date.

When we bought our home, we tried to negotiate with the seller to discount the home price if we agreed to pay all costs (including agent fees) to reduce the assessed value. But the seller didn’t want to deal with the hassle.