Do flippers account for this type of cost in their deal analysis?

[Jose Falconett]

So if a flipper is buying cash from a motivated distressed seller... The investor would then pay the closing costs of both the seller's and their own closing cost's for the initial PURCHASE (at least that is what is most common).

Now for the SALE of the flip at the intended ARV...

Does the flipper account to pay the retail buyers closing costs and their own once again? If not what cost's are commonly and typically accounted for the retail sale?