If Grant Deed Sale instead of Foreclosure or In Lieu of, how are the costs of title transfer and default addressed and how are property taxes affected

He wants to sell the property back to you? He has no title to the property unless you foolishly transferred it to him [as that would mean you only have a contract with him and no claim on the property]. So legally he has nothing to sell. If you "buy" the property from him, you would have to pay for a title search to be sure he has not encumbered the property [you could do that yourself[, transfer taxes, the property would be reassessed [after 10 years it should be worth a lot more so your property taxes will likely double]. There is almost no advantage to you, so you should not help him from being labeled with a foreclosure.