First, the answer will be impacted by how much other income you have and your state of residence. Maryland's rate appears to be 4.75% over $3,001. The Federal rate can be 0% if you have held the property for more than 1 year and your marginal rate is 10% or 15%; otherwise it will be 15%. However, there are several special rules. For that reason you must retain a competent CPA to prepare your tax projections and to prepare your tax returns.
Second, each person pays the rate due based on that person's facts.
Third, signing a quitclaim deed may constitute a gift. If the gift occurs before the sale, then the donee (the person in favor of whom the quitclaim was made) will have the same basis (for purposes of the sale) that the donor had.